Table of Contents
graph - 2D graph for plotting
X-Y coordinate data.
graph pathName ?option value?...
The
graph command creates a graph for plotting two-dimensional data (X-Y coordinates).
It has many configurable components: coordinate axes, elements, legend,
grid lines, cross hairs, etc. They allow you to customize the look and
feel of the graph.
The graph command creates a new window for
plotting two-dimensional data (X-Y coordinates). Data points are plotted
in a rectangular area displayed in the center of the new window. This is
the plotting area. The coordinate axes are drawn in the margins around
the plotting area. By default, the legend is displayed in the right margin.
The title is displayed in top margin.
The graph widget is composed of several
components: coordinate axes, data elements, legend, grid, cross hairs,
pens, postscript, and annotation markers.
- axis
- The graph has four standard
axes (x, x2, y, and y2), but you can create and display any number
of axes. Axes control what region of data is displayed and how the data
is scaled. Each axis consists of the axis line, title, major and minor ticks,
and tick labels. Tick labels display the value at each major tick.
- crosshairs
- Cross hairs are used to position the mouse pointer relative to the X and
Y coordinate axes. Two perpendicular lines, intersecting at the current
location of the mouse, extend across the plotting area to the coordinate
axes.
- element
- An element represents a set of data points. Elements can
be plotted with a symbol at each data point and lines connecting the points.
The appearance of the element, such as its symbol, line width, and color
is configurable.
- grid
- Extends the major and minor ticks of the X-axis and/or
Y-axis across the plotting area.
- legend
- The legend displays the name
and symbol of each data element. The legend can be drawn in any margin
or in the plotting area.
- marker
- Markers are used annotate or highlight
areas of the graph. For example, you could use a polygon marker to fill
an area under a curve, or a text marker to label a particular data point.
Markers come in various forms: text strings, bitmaps, connected line
segments, images, polygons, or embedded widgets.
- pen
- Pens define attributes
(both symbol and line style) for elements. Data elements use pens to specify
how they should be drawn. A data element may use many pens at once. Here,
the particular pen used for a data point is determined from each element's
weight vector (see the element's -weight and -style options).
- postscript
- The widget can generate encapsulated PostScript output. This component has
several options to configure how the PostScript is generated.
graph pathName ?option value?...
The graph command creates a new window pathName and makes it into a graph
widget. At the time this command is invoked, there must not exist a window
named pathName, but pathName's parent must exist. Additional options may
be specified on the command line or in the option database to configure
aspects of the graph such as its colors and font. See the configure operation
below for the exact details about what option and value pairs are valid.
If successful, graph returns the path name of the widget. It also creates
a new Tcl command by the same name. You can use this command to invoke
various operations that query or modify the graph. The general form is:
pathName operation ?arg?...
Both operation and its arguments determine the exact behavior of the command.
The operations available for the graph are described in the GRAPH OPERATIONS
section.
The command can also be used to access components of the graph.
pathName component operation ?arg?...
The operation, now located after the name of the component, is the function
to be performed on that component. Each component has its own set of operations
that manipulate that component. They will be described below in their own
sections.
The graph command creates a new graph.
# Create a new graph. Plotting area is black.
graph .g -plotbackground black
A new Tcl command .g is also created. This command can be used to query
and modify the graph. For example, to change the title of the graph to
"My Plot", you use the new command and the graph's configure operation.
# Change the title.
.g configure -title "My Plot"
A graph has several components. To access a particular component you use
the component's name. For example, to add data elements, you use the new
command and the element component.
# Create a new element named "line1"
.g element create line1 \
-xdata { 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 } \
-ydata { 26.18 50.46 72.85 93.31 111.86 128.47 143.14
155.85 166.60 175.38 }
The element's X-Y coordinates are specified using lists of numbers. Alternately,
BLT vectors could be used to hold the X-Y coordinates.
# Create two vectors and add them to the graph.
vector xVec yVec
xVec set { 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 }
yVec set { 26.18 50.46 72.85 93.31 111.86 128.47 143.14 155.85
166.60 175.38 }
.g element create line1 -xdata xVec -ydata yVec
The advantage of using vectors is that when you modify one, the graph is
automatically redrawn to reflect the new values.
# Change the y coordinate of the first point.
set yVector(0) 25.18
An element named e1 is now created in .b. It is automatically added
to the display list of elements. You can use this list to control in what
order elements are displayed. To query or reset the element display list,
you use the element's show operation.
# Get the current display list
set elemList [.b element show]
# Remove the first element so it won't be displayed.
.b element show [lrange $elemList 0 end]
The element will be displayed by as many bars as there are data points
(in this case there are ten). The bars will be drawn centered at the x-coordinate
of the data point. All the bars will have the same attributes (colors,
stipple, etc). The width of each bar is by default one unit. You can change
this with using the -barwidth option.
# Change the X-Y coordinates of the first point.
set xVec(0) 0.18
set yVec(0) 25.18
An element named line1 is now created in .g. By default, the element's
label in the legend will be also line1. You can change the label, or specify
no legend entry, again using the element's configure operation.
# Don't display "line1" in the legend.
.g element configure line1 -label ""
You can configure more than just the element's label. An element has many
attributes such as symbol type and size, dashed or solid lines, colors,
line width, etc.
.g element configure line1 -symbol square -color red \
-dashes { 2 4 2 } -linewidth 2 -pixels 2c
Four coordinate axes are automatically created: x, x2, y, and y2.
And by default, elements are mapped onto the axes x and y. This can
be changed with the -mapx and -mapy options.
# Map "line1" on the alternate Y-axis "y2".
.g element configure line1 -mapy y2
Axes can be configured in many ways too. For example, you change the scale
of the Y-axis from linear to log using the axis component.
# Y-axis is log scale.
.g axis configure y -logscale yes
One important way axes are used is to zoom in on a particular data region.
Zooming is done by simply specifying new axis limits using the -min and
-max configuration options.
.g axis configure x -min 1.0 -max 1.5
.g axis configure y -min 12.0 -max 55.15
To zoom interactively, you link the axis configure operations with some
user interaction (such as pressing the mouse button), using the bind command.
To convert between screen and graph coordinates, use the invtransform
operation.
# Click the button to set a new minimum
bind .g <ButtonPress-1> {
%W axis configure x -min [%W axis invtransform x %x]
%W axis configure x -min [%W axis invtransform x %y]
}
By default, the limits of the axis are determined from data values. To reset
back to the default limits, set the -min and -max options to the empty value.
# Reset the axes to autoscale again.
.g axis configure x -min {} -max {}
.g axis configure y -min {} -max {}
By default, the legend is drawn in the right margin. You can change this
or any legend configuration options using the legend component.
# Configure the legend font, color, and relief
.g legend configure -position left -relief raised \
-font fixed -fg blue
To prevent the legend from being displayed, turn on the -hide option.
# Don't display the legend.
.g legend configure -hide yes
The graph widget has simple drawing procedures called markers. They can
be used to highlight or annotate data in the graph. The types of markers
available are bitmaps, images, polygons, lines, or windows. Markers can
be used, for example, to mark or brush points. In this example, is a text
marker that labels the data first point. Markers are created using the
marker component.
# Create a label for the first data point of "line1".
.g marker create text -name first_marker -coords { 0.2 26.18 } \
-text "start" -anchor se -xoffset -10 -yoffset -10
This creates a text marker named first_marker. It will display the text
"start" near the coordinates of the first data point. The -anchor, -xoffset,
and -yoffset options are used to display the marker above and to the left
of the data point, so that the data point isn't covered by the marker. By
default, markers are drawn last, on top of data. You can change this with
the -under option.
# Draw the label before elements are drawn.
.g marker configure first_marker -under yes
You can add cross hairs or grid lines using the crosshairs and grid components.
# Display both cross hairs and grid lines.
.g crosshairs configure -hide no -color red
.g grid configure -hide no -dashes { 2 2 }
# Set up a binding to reposition the crosshairs.
bind .g <Motion> {
.g crosshairs configure -position @%x,%y
}
The crosshairs are repositioned as the mouse pointer is moved in the graph.
The pointer X-Y coordinates define the center of the crosshairs.
Finally,
to get hardcopy of the graph, use the postscript component.
# Print the graph into file "file.ps"
.g postscript output file.ps -maxpect yes -decorations no
This generates a file file.ps containing the encapsulated PostScript of
the graph. The option -maxpect says to scale the plot to the size of the
page. Turning off the -decorations option denotes that no borders or color
backgrounds should be drawn (i.e. the background of the margins, legend,
and plotting area will be white).
- pathName axis operation
?arg?...
- See the AXIS COMPONENTS
section.
- pathName bar elemName ?option value?...
- Creates a new barchart element elemName. It's an error if an element elemName
already exists. See the manual for barchart for details about what option
and value pairs are valid.
- pathName cget option
- Returns the current value
of the configuration option given by option. Option may be any option described
below for the configure operation.
- pathName configure ?option value?...
- Queries
or modifies the configuration options of the graph. If option isn't specified,
a list describing the current options for pathName is returned. If option
is specified, but not value, then a list describing option is returned.
If one or more option and value pairs are specified, then for each pair,
the option option is set to value. The following options are valid.
- -aspect
width/height
- Force a fixed aspect ratio of width/height, a floating point
number.
- -background color
- Sets the background color. This includes the margins
and legend, but not the plotting area.
- -borderwidth pixels
- Sets the width
of the 3-D border around the outside edge of the widget. The -relief option
determines if the border is to be drawn. The default is 2.
- -bottommargin
pixels
- If non-zero, overrides the computed size of the margin extending
below the X-coordinate axis. If pixels is 0, the automatically computed
size is used. The default is 0.
- -bufferelements boolean
- Indicates whether
an internal pixmap to buffer the display of data elements should be used.
If boolean is true, data elements are drawn to an internal pixmap. This
option is especially useful when the graph is redrawn frequently while
the remains data unchanged (for example, moving a marker across the plot).
See the SPEED TIPS
section. The default is 1.
- -cursor cursor
- Specifies
the widget's cursor. The default cursor is crosshair.
- -font fontName
- Specifies
the font of the graph title. The default is *-Helvetica-Bold-R-Normal-*-18-180-*.
- -halo pixels
- Specifies a maximum distance to consider when searching for
the closest data point (see the element's closest operation below). Data
points further than pixels away are ignored. The default is 0.5i.
- -height
pixels
- Specifies the requested height of widget. The default is 4i.
- -invertxy
boolean
- Indicates whether the placement X-axis and Y-axis should be inverted.
If boolean is true, the X and Y axes are swapped. The default is 0.
- -justify
justify
- Specifies how the title should be justified. This matters only
when the title contains more than one line of text. Justify must be left,
right, or center. The default is center.
- -leftmargin pixels
- If non-zero,
overrides the computed size of the margin extending from the left edge
of the window to the Y-coordinate axis. If pixels is 0, the automatically
computed size is used. The default is 0.
- -plotbackground color
- Specifies
the background color of the plotting area. The default is white.
- -plotborderwidth
pixels
- Sets the width of the 3-D border around the plotting area. The -plotrelief
option determines if a border is drawn. The default is 2.
- -plotpadx pad
- Sets the amount of padding to be added to the left and right sides of the
plotting area. Pad can be a list of one or two screen distances. If pad
has two elements, the left side of the plotting area entry is padded by
the first distance and the right side by the second. If pad is just one
distance, both the left and right sides are padded evenly. The default
is 8.
- -plotpady pad
- Sets the amount of padding to be added to the top and
bottom of the plotting area. Pad can be a list of one or two screen distances.
If pad has two elements, the top of the plotting area is padded by the
first distance and the bottom by the second. If pad is just one distance,
both the top and bottom are padded evenly. The default is 8.
- -plotrelief
relief
- Specifies the 3-D effect for the plotting area. Relief specifies
how the interior of the plotting area should appear relative to rest of
the graph; for example, raised means the plot should appear to protrude
from the graph, relative to the surface of the graph. The default is sunken.
- -relief relief
- Specifies the 3-D effect for the graph widget. Relief specifies
how the graph should appear relative to widget it is packed into; for example,
raised means the graph should appear to protrude. The default is flat.
- -rightmargin pixels
- If non-zero, overrides the computed size of the margin
extending from the plotting area to the right edge of the window. By default,
the legend is drawn in this margin. If pixels is 0, the automatically
computed size is used. The default is 0.
- -takefocus focus
- Provides information
used when moving the focus from window to window via keyboard traversal
(e.g., Tab and Shift-Tab). If focus is 0, this means that this window should
be skipped entirely during keyboard traversal. 1 means that the this
window should always receive the input focus. An empty value means that
the traversal scripts make the decision whether to focus on the window.
The default is "".
- -tile image
- Specifies a tiled background for the widget.
If image isn't "", the background is tiled using image. Otherwise, the
normal background color is drawn (see the -background option). Image must
be an image created using the Tk image command. The default is "".
- -title
text
- Sets the title to text. If text is "", no title will be displayed.
- -topmargin pixels
- If non-zero, overrides the computed size of the margin
above the x2 axis. If pixels is 0, the automatically computed size is
used. The default is 0.
- -width pixels
- Specifies the requested width of
the widget. The default is 5i.
- pathName crosshairs operation ?arg?
- See
the CROSSHAIRS COMPONENT
section.
- pathName element operation ?arg?...
- See
the ELEMENT COMPONENTS
section.
- pathName extents item
- Returns the size
of a particular item in the graph. Item must be either leftmargin, rightmargin,
topmargin, bottommargin, plotwidth, or plotheight.
- pathName grid
operation ?arg?...
- See the GRID COMPONENT
section.
- pathName invtransform
winX winY
- Performs an inverse coordinate transformation, mapping window
coordinates back to graph coordinates, using the standard X-axis and Y-axis.
Returns a list of containing the X-Y graph coordinates.
- pathName inside x
y
- Returns 1 is the designated screen coordinate (x and y) is inside the
plotting area and 0 otherwise.
- pathName legend operation ?arg?...
- See the
LEGEND COMPONENT
section.
- pathName line operation arg...
- The operation is
the same as element.
- pathName marker operation ?arg?...
- See the MARKER COMPONENTS
section.
- pathName postscript operation ?arg?...
- See the POSTSCRIPT COMPONENT
section.
- pathName snap ?switches? outputName
- Takes a snapshot of the graph,
saving the output in outputName. The following switches are available.
- -format
format
- Specifies how the snapshot is output. Format may be one of the following
listed below. The default is photo.
- photo
- Saves a Tk photo image. OutputName
represents the name of a Tk photo image that must already have been created.
- wmf
- Saves an Aldus Placeable Metafile. OutputName represents the filename
where the metafile is written. If outputName is CLIPBOARD, then output
is written directly to the Windows clipboard. This format is available
only under Microsoft Windows.
- emf
- Saves an Enhanced Metafile. OutputName
represents the filename where the metafile is written. If outputName is
CLIPBOARD, then output is written directly to the Windows clipboard.
This format is available only under Microsoft Windows.
- -height size
- Specifies
the height of the graph. Size is a screen distance. The graph will be redrawn
using this dimension, rather than its current window height.
- -width size
- Specifies the width of the graph. Size is a screen distance. The graph will
be redrawn using this dimension, rather than its current window width.
- pathName
transform x y
- Performs a coordinate transformation, mapping graph coordinates
to window coordinates, using the standard X-axis and Y-axis. Returns a list
containing the X-Y screen coordinates.
- pathName xaxis operation ?arg?...
- pathName
x2axis operation ?arg?...
- pathName yaxis operation ?arg?...
- pathName y2axis
operation ?arg?...
- See the AXIS COMPONENTS
section.
A graph
is composed of several components: coordinate axes, data elements, legend,
grid, cross hairs, postscript, and annotation markers. Instead of one big
set of configuration options and operations, the graph is partitioned,
where each component has its own configuration options and operations that
specifically control that aspect or part of the graph.
Four
coordinate axes are automatically created: two X-coordinate axes (x and
x2) and two Y-coordinate axes (y, and y2). By default, the axis x
is located in the bottom margin, y in the left margin, x2 in the top
margin, and y2 in the right margin.
An axis consists of the axis line,
title, major and minor ticks, and tick labels. Major ticks are drawn at
uniform intervals along the axis. Each tick is labeled with its coordinate
value. Minor ticks are drawn at uniform intervals within major ticks.
The range of the axis controls what region of data is plotted. Data points
outside the minimum and maximum limits of the axis are not plotted. By
default, the minimum and maximum limits are determined from the data, but
you can reset either limit.
You can have several axes. To create an axis,
invoke the axis component and its create operation.
# Create a new axis called "tempAxis"
.g axis create tempAxis
You map data elements to an axis using the element's -mapy and -mapx configuration
options. They specify the coordinate axes an element is mapped onto.
# Now map the tempAxis data to this axis.
.g element create "e1" -xdata $x -ydata $y -mapy tempAxis
Any number of axes can be displayed simultaneously. They are drawn in the
margins surrounding the plotting area. The default axes x and y are
drawn in the bottom and left margins. The axes x2 and y2 are drawn in
top and right margins. By default, only x and y are shown. Note that
the axes can have different scales.
To display a different axis or more
than one axis, you invoke one of the following components: xaxis, yaxis,
x2axis, and y2axis. Each component has a use operation that designates
the axis (or axes) to be drawn in that corresponding margin: xaxis in the
bottom, yaxis in the left, x2axis in the top, and y2axis in the right.
# Display the axis tempAxis in the left margin.
.g yaxis use tempAxis
The use operation takes a list of axis names as its last argument. This
is the list of axes to be drawn in this margin.
You can configure axes in
many ways. The axis scale can be linear or logarithmic. The values along
the axis can either monotonically increase or decrease. If you need custom
tick labels, you can specify a Tcl procedure to format the label any way
you wish. You can control how ticks are drawn, by changing the major tick
interval or the number of minor ticks. You can define non-uniform tick intervals,
such as for time-series plots.
- pathName axis bind tagName ?sequence? ?command?
- Associates command with tagName such that whenever the event sequence
given by sequence occurs for an axis with this tag, command will be invoked.
The syntax is similar to the bind command except that it operates on
graph axes, rather than widgets. See the bind manual entry for complete
details on sequence and the substitutions performed on command before
invoking it.
If all arguments are specified then a new binding is created,
replacing any existing binding for the same sequence and tagName. If the
first character of command is + then command augments an existing binding
rather than replacing it. If no command argument is provided then the command
currently associated with tagName and sequence (it's an error occurs if
there's no such binding) is returned. If both command and sequence are
missing then a list of all the event sequences for which bindings have
been defined for tagName.
- pathName axis cget axisName option
- Returns the
current value of the option given by option for axisName. Option may be
any option described below for the axis configure operation.
- pathName axis
configure axisName ?axisName?... ?option value?...
- Queries or modifies the configuration
options of axisName. Several axes can be changed. If option isn't specified,
a list describing all the current options for axisName is returned. If
option is specified, but not value, then a list describing option is returned.
If one or more option and value pairs are specified, then for each pair,
the axis option option is set to value. The following options are valid
for axes.
- -bindtags tagList
- Specifies the binding tags for the axis. TagList
is a list of binding tag names. The tags and their order will determine
how events for axes are handled. Each tag in the list matching the current
event sequence will have its Tcl command executed. Implicitly the name
of the element is always the first tag in the list. The default value is
all.
- -color color
- Sets the color of the axis and tick labels. The default
is black.
- -command prefix
- Specifies a Tcl command to be invoked when formatting
the axis tick labels. Prefix is a string containing the name of a Tcl proc
and any extra arguments for the procedure. This command is invoked for
each major tick on the axis. Two additional arguments are passed to the
procedure: the pathname of the widget and the current the numeric value
of the tick. The procedure returns the formatted tick label. If "" is
returned, no label will appear next to the tick. You can get the standard
tick labels again by setting prefix to "". The default is "".
Please
note that this procedure is invoked while the graph is redrawn. You may
query configuration options. But do not them, because this can have unexpected
results.
- -descending boolean
- Indicates whether the values along the axis
are monotonically increasing or decreasing. If boolean is true, the axis
values will be decreasing. The default is 0.
- -hide boolean
- Indicates if
the axis is displayed. If boolean is false the axis will be displayed. Any
element mapped to the axis is displayed regardless. The default value is
0.
- -justify justify
- Specifies how the axis title should be justified. This
matters only when the axis title contains more than one line of text. Justify
must be left, right, or center. The default is center.
- -limits formatStr
- Specifies a printf-like description to format the minimum and maximum limits
of the axis. The limits are displayed at the top/bottom or left/right sides
of the plotting area. FormatStr is a list of one or two format descriptions.
If one description is supplied, both the minimum and maximum limits are
formatted in the same way. If two, the first designates the format for
the minimum limit, the second for the maximum. If "" is given as either
description, then the that limit will not be displayed. The default is
"".
- -linewidth pixels
- Sets the width of the axis and tick lines. The default
is 1 pixel.
- -logscale boolean
- Indicates whether the scale of the axis is
logarithmic or linear. If boolean is true, the axis is logarithmic. The
default scale is linear.
- -loose boolean
- Indicates whether the limits of the
axis should fit the data points tightly, at the outermost data points,
or loosely, at the outer tick intervals. If the axis limit is set with the
-min or -max option, the axes are displayed tightly. If boolean is true, the
axis range is "loose". The default is 0.
- -majorticks majorList
- Specifies
where to display major axis ticks. You can use this option to display ticks
at non-uniform intervals. MajorList is a list of axis coordinates designating
the location of major ticks. No minor ticks are drawn. If majorList is
"", major ticks will be automatically computed. The default is "".
- -max
value
- Sets the maximum limit of axisName. Any data point greater than
value is not displayed. If value is "", the maximum limit is calculated
using the largest data value. The default is "".
- -min value
- Sets the minimum
limit of axisName. Any data point less than value is not displayed. If
value is "", the minimum limit is calculated using the smallest data
value. The default is "".
- -minorticks minorList
- Specifies where to display
minor axis ticks. You can use this option to display minor ticks at non-uniform
intervals. MinorList is a list of real values, ranging from 0.0 to 1.0, designating
the placement of a minor tick. No minor ticks are drawn if the -majortick
option is also set. If minorList is "", minor ticks will be automatically
computed. The default is "".
- -rotate theta
- Specifies the how many degrees
to rotate the axis tick labels. Theta is a real value representing the number
of degrees to rotate the tick labels. The default is 0.0 degrees.
- -scrollcommand
command
- Specify the prefix for a command used to communicate with scrollbars
for this axis, such as .sbar set.
- -scrollmax value
- Sets the maximum limit
of the axis scroll region. If value is "", the maximum limit is calculated
using the largest data value. The default is "".
- -scrollmin value
- Sets
the minimum limit of axis scroll region. If value is "", the minimum
limit is calculated using the smallest data value. The default is "".
- -showticks boolean
- Indicates whether axis ticks should be drawn. If boolean
is true, ticks are drawn. If false, only the axis line is drawn. The default
is 1.
- -stepsize value
- Specifies the interval between major axis ticks.
If value isn't a valid interval (must be less than the axis range), the
request is ignored and the step size is automatically calculated.
- -subdivisions
number
- Indicates how many minor axis ticks are to be drawn. For example,
if number is two, only one minor tick is drawn. If number is one, no minor
ticks are displayed. The default is 2.
- -tickfont fontName
- Specifies the
font for axis tick labels. The default is *-Courier-Bold-R-Normal-*-100-*.
- -ticklength
pixels
- Sets the length of major and minor ticks (minor ticks are half the
length of major ticks). If pixels is less than zero, the axis will be inverted
with ticks drawn pointing towards the plot. The default is 0.1i.
- -title
text
- Sets the title of the axis. If text is "", no axis title will be
displayed.
- -titlealternate boolean
- Indicates to display the axis title
in its alternate location. Normally the axis title is centered along the
axis. This option places the axis either to the right (horizontal axes)
or above (vertical axes) the axis. The default is 0.
- -titlecolor color
- Sets the color of the axis title. The default is black.
- -titlefont fontName
- Specifies the font for axis title. The default is *-Helvetica-Bold-R-Normal-*-14-140-*.
Axis configuration options may be also be set by the option command. The
resource class is Axis. The resource names are the names of the axes
(such as x or x2).
option add *Graph.Axis.Color blue
option add *Graph.x.LogScale true
option add *Graph.x2.LogScale false
pathName axis create axisName ?option value?...
Creates a new axis by the
name axisName. No axis by the same name can already exist. Option and value
are described in above in the axis configure operation.
pathName axis delete
?axisName?...
Deletes the named axes. An axis is not really deleted until it
is not longer in use, so it's safe to delete axes mapped to elements.
pathName
axis invtransform axisName value
Performs the inverse transformation, changing
the screen coordinate value to a graph coordinate, mapping the value mapped
to axisName. Returns the graph coordinate.
pathName axis limits axisName
Returns a list of the minimum and maximum limits for axisName. The order
of the list is min max.
pathName axis names ?pattern?...
Returns a list of
axes matching zero or more patterns. If no pattern argument is give, the
names of all axes are returned.
pathName axis transform axisName value
Transforms
the coordinate value to a screen coordinate by mapping the it to axisName.
Returns the transformed screen coordinate.
pathName axis view axisName
Change the viewable area of this axis. Use as an argument to a scrollbar's
"-command".
The default axes are x, y, x2, and y2. But you can display
more than four axes simultaneously. You can also swap in a different axis
with use operation of the special axis components: xaxis, x2axis, yaxis,
and y2axis.
.g create axis temp
.g create axis time
...
.g xaxis use temp
.g yaxis use time
Only the axes specified for use are displayed on the screen.
The xaxis,
x2axis, yaxis, and y2axis components operate on an axis location rather
than a specific axis like the more general axis component does. They implicitly
control the axis that is currently using to that location. By default,
xaxis uses the x axis, yaxis uses y, x2axis uses x2, and y2axis uses
y2. When more than one axis is displayed in a margin, it represents the
first axis displayed.
The following operations are available for axes. They
mirror exactly the operations of the axis component. The axis argument
must be xaxis, x2axis, yaxis, or y2axis. This feature is deprecated since
more than one axis can now be used a margin. You should only use the xaxis,
x2axis, yaxis, and y2axis components with the use operation. For all other
operations, use the general axis component instead.
- pathName axis cget option
- pathName axis configure ?option value?...
- pathName axis invtransform value
- pathName axis limits
- pathName axis transform value
- pathName axis use ?axisName?
- Designates the axis axisName is to be displayed at this location. AxisName
can not be already in use at another location. This command returns the
name of the axis currently using this location.
Cross
hairs consist of two intersecting lines (one vertical and one horizontal)
drawn completely across the plotting area. They are used to position the
mouse in relation to the coordinate axes. Cross hairs differ from line
markers in that they are implemented using XOR drawing primitives. This
means that they can be quickly drawn and erased without redrawing the entire
graph. Note that crosshair are enabled by calling Blt_Crosshairs and turned
off by calling Blt_ResetCrosshairs. Similarly call Blt_ZoomStack for zooming.
The following operations are available for cross hairs:
- pathName crosshairs
cget option
- Returns the current value of the cross hairs configuration
option given by option. Option may be any option described below for the
cross hairs configure operation.
- pathName crosshairs configure ?option value?...
- Queries or modifies the configuration options of the cross hairs. If
option isn't specified, a list describing all the current options for the
cross hairs is returned. If option is specified, but not value, then a
list describing option is returned. If one or more option and value pairs
are specified, then for each pair, the cross hairs option option is set
to value. The following options are available for cross hairs.
- -color color
- Sets the color of the cross hairs. The default is black.
- -dashes dashList
- Sets the dash style of the cross hairs. DashList is a list of up to 11 numbers
that alternately represent the lengths of the dashes and gaps on the cross
hair lines. Each number must be between 1 and 255. If dashList is "",
the cross hairs will be solid lines.
- -hide boolean
- Indicates whether cross
hairs are drawn. If boolean is true, cross hairs are not drawn. The default
is yes.
- -linewidth pixels
- Set the width of the cross hair lines. The default
is 1.
- -position pos
- Specifies the screen position where the cross hairs
intersect. Pos must be in the form "@x,y", where x and y are the window
coordinates of the intersection.
Cross hairs configuration options may be
also be set by the option command. The resource name and class are crosshairs
and Crosshairs respectively.
option add *Graph.Crosshairs.LineWidth 2
option add *Graph.Crosshairs.Color red
pathName crosshairs off
Turns off the cross hairs.
pathName crosshairs
on
Turns on the display of the cross hairs.
pathName crosshairs toggle
Toggles the current state of the cross hairs, alternately mapping and unmapping
the cross hairs.
A data element represents a set of data.
It contains x and y vectors containing the coordinates of the data points.
Elements can be displayed with a symbol at each data point and lines connecting
the points. Elements also control the appearance of the data, such as the
symbol type, line width, color etc.
When new data elements are created,
they are automatically added to a list of displayed elements. The display
list controls what elements are drawn and in what order.
The following
operations are available for elements.
- pathName element activate elemName
?index?...
- Specifies the data points of element elemName to be drawn using
active foreground and background colors. ElemName is the name of the element
and index is a number representing the index of the data point. If no indices
are present then all data points become active.
- pathName element bind tagName
?sequence? ?command?
- Associates command with tagName such that whenever
the event sequence given by sequence occurs for an element with this tag,
command will be invoked. The syntax is similar to the bind command except
that it operates on graph elements, rather than widgets. See the bind manual
entry for complete details on sequence and the substitutions performed
on command before invoking it.
If all arguments are specified then a
new binding is created, replacing any existing binding for the same sequence
and tagName. If the first character of command is + then command augments
an existing binding rather than replacing it. If no command argument is
provided then the command currently associated with tagName and sequence
(it's an error occurs if there's no such binding) is returned. If both command
and sequence are missing then a list of all the event sequences for which
bindings have been defined for tagName.
- pathName element cget elemName
option
- Returns the current value of the element configuration option given
by option. Option may be any of the options described below for the element
configure operation.
- pathName element closest x y varName ?option value?...
?elemName?...
Searches for the data point closest to the window coordinates
x and y. By default, all elements are searched. Hidden elements (see the
-hide option is false) are ignored. You can limit the search by specifying
only the elements you want to be considered. ElemName must be the name
of an element that is not be hidden. VarName is the name of a Tcl array
variable and will contain the search results: the name of the closest element,
the index of the closest data point, and the graph coordinates of the point.
Returns 0, if no data point within the threshold distance can be found,
otherwise 1 is returned. The following option-value pairs are available.
- -along direction
- Search for the closest element using the following criteria:
- x
- Find closest element vertically from the given X-coordinate.
- y
- Find
the closest element horizontally from the given Y-coordinate.
- both
- Find
the closest element for the given point (using both the X and Y coordinates).
- -halo pixels
- Specifies a threshold distance where selected data points
are ignored. Pixels is a valid screen distance, such as 2 or 1.2i. If
this option isn't specified, then it defaults to the value of the graph's
-halo option.
- -interpolate string
- Indicates whether to consider projections
that lie along the line segments connecting data points when searching
for the closest point. The default value is 0. The values for string are
described below.
- no
- Search only for the closest data point.
- yes
- Search
includes projections that lie along the line segments connecting the data
points.
- pathName element configure elemName ?elemName... ?option value?...
- Queries
or modifies the configuration options for elements. Several elements can
be modified at the same time. If option isn't specified, a list describing
all the current options for elemName is returned. If option is specified,
but not value, then a list describing the option option is returned. If
one or more option and value pairs are specified, then for each pair, the
element option option is set to value. The following options are valid
for elements.
- -activepen penName
- Specifies pen to use to draw active element.
If penName is "", no active elements will be drawn. The default is
activeLine.
- -bindtags tagList
- Specifies the binding tags for the element.
TagList is a list of binding tag names. The tags and their order will
determine how events are handled for elements. Each tag in the list matching
the current event sequence will have its Tcl command executed. Implicitly
the name of the element is always the first tag in the list. The default
value is all.
- -color color
- Sets the color of the traces connecting the
data points.
- -dashes dashList
- Sets the dash style of element line. DashList
is a list of up to 11 numbers that alternately represent the lengths of
the dashes and gaps on the element line. Each number must be between 1
and 255. If dashList is "", the lines will be solid.
- -data coordList
- Specifies
the X-Y coordinates of the data. CoordList is a list of numeric expressions
representing the X-Y coordinate pairs of each data point.
- -fill color
- Sets
the interior color of symbols. If color is "", then the interior of the
symbol is transparent. If color is defcolor, then the color will be the
same as the -color option. The default is defcolor.
- -hide boolean
- Indicates
whether the element is displayed. The default is no.
- -label text
- Sets
the element's label in the legend. If text is "", the element will have
no entry in the legend. The default label is the element's name.
- -linewidth
pixels
- Sets the width of the connecting lines between data points. If
pixels is 0, no connecting lines will be drawn between symbols. The default
is 0.
- -mapx xAxis
- Selects the X-axis to map the element's X-coordinates onto.
XAxis must be the name of an axis. The default is x.
- -mapy yAxis
- Selects
the Y-axis to map the element's Y-coordinates onto. YAxis must be the name
of an axis. The default is y.
- -offdash color
- Sets the color of the stripes
when traces are dashed (see the -dashes option). If color is "", then
the "off" pixels will represent gaps instead of stripes. If color is defcolor,
then the color will be the same as the -color option. The default is defcolor.
- -outline color
- Sets the color or the outline around each symbol. If color
is "", then no outline is drawn. If color is defcolor, then the color
will be the same as the -color option. The default is defcolor.
- -pen penname
- Set the pen to use for this element.
- -outlinewidth pixels
- Sets the width
of the outline bordering each symbol. If pixels is 0, no outline will
be drawn. The default is 1.
- -pixels pixels
- Sets the size of symbols. If
pixels is 0, no symbols will be drawn. The default is 0.125i.
- -scalesymbols
boolean
- If boolean is true, the size of the symbols drawn for elemName
will change with scale of the X-axis and Y-axis. At the time this option is
set, the current ranges of the axes are saved as the normalized scales
(i.e scale factor is 1.0) and the element is drawn at its designated size
(see the -pixels option). As the scale of the axes change, the symbol will
be scaled according to the smaller of the X-axis and Y-axis scales. If boolean
is false, the element's symbols are drawn at the designated size, regardless
of axis scales. The default is 0.
- -smooth smooth
- Specifies how connecting
line segments are drawn between data points. Smooth can be either linear,
step, natural, or quadratic. If smooth is linear, a single line
segment is drawn, connecting both data points. When smooth is step, two
line segments are drawn. The first is a horizontal line segment that steps
the next X-coordinate. The second is a vertical line, moving to the next
Y-coordinate. Both natural and quadratic generate multiple segments between
data points. If natural, the segments are generated using a cubic spline.
If quadratic, a quadratic spline is used. The default is linear.
- -styles
styleList
- Specifies what pen to use based on the range of weights given.
StyleList is a list of style specifications. Each style specification, in
turn, is a list consisting of a pen name, and optionally a minimum and
maximum range. Data points whose weight (see the -weight option) falls in
this range, are drawn with this pen. If no range is specified it defaults
to the index of the pen in the list. Note that this affects only symbol
attributes. Line attributes, such as line width, dashes, etc. are ignored.
- -symbol symbol
- Specifies the symbol for data points. Symbol can be either
square, circle, diamond, plus, cross, splus, scross, triangle,
"" (where no symbol is drawn), or a bitmap. Bitmaps are specified as
"source ?mask?", where source is the name of the bitmap, and mask is the
bitmap's optional mask. The default is circle.
- -trace direction
- Indicates
whether connecting lines between data points (whose X-coordinate values
are either increasing or decreasing) are drawn. Direction must be increasing,
decreasing, or both. For example, if direction is increasing, connecting
lines will be drawn only between those data points where X-coordinate values
are monotonically increasing. If direction is both, connecting lines
will be draw between all data points. The default is both.
- -weights wVec
- Specifies the weights of the individual data points. This, with the list
pen styles (see the -styles option), controls how data points are drawn.
WVec is the name of a BLT vector or a list of numeric expressions representing
the weights for each data point.
- -xdata xVec
- Specifies the X-coordinates
of the data. XVec is the name of a BLT vector or a list of numeric expressions.
- -ydata yVec
- Specifies the Y-coordinates of the data. YVec is the name of
a BLT vector or a list of numeric expressions.
Element configuration options
may also be set by the option command. The resource class is Element.
The resource name is the name of the element.
option add *Graph.Element.symbol line
option add *Graph.e1.symbol line
pathName element create elemName ?option value?...
Creates a new element elemName.
It's an error is an element elemName already exists. If additional arguments
are present, they specify options valid for the element configure operation.
pathName element deactivate elemName ?elemName?...
Deactivates all the elements
matching pattern. Elements whose names match any of the patterns given are
redrawn using their normal colors.
pathName element delete ?elemName?...
Deletes
all the named elements. The graph is automatically redrawn.
pathName element
exists elemName
Returns 1 if an element elemName currently exists and
0 otherwise.
pathName element names ?pattern?...
Returns the elements matching
one or more pattern. If no pattern is given, the names of all elements
is returned.
pathName element show ?nameList?
Queries or modifies the
element display list. The element display list designates the elements
drawn and in what order. NameList is a list of elements to be displayed
in the order they are named. If there is no nameList argument, the current
display list is returned.
pathName element type elemName
Returns the type
of elemName. If the element is a bar element, the commands returns the
string "bar", otherwise it returns "line".
Grid lines
extend from the major and minor ticks of each axis horizontally or vertically
across the plotting area. The following operations are available for grid
lines.
- pathName grid cget option
- Returns the current value of the grid line
configuration option given by option. Option may be any option described
below for the grid configure operation.
- pathName grid configure ?option
value?...
- Queries or modifies the configuration options for grid lines. If
option isn't specified, a list describing all the current grid options for
pathName is returned. If option is specified, but not value, then a list
describing option is returned. If one or more option and value pairs are
specified, then for each pair, the grid line option option is set to value.
The following options are valid for grid lines.
- -color color
- Sets the color
of the grid lines. The default is black.
- -dashes dashList
- Sets the dash
style of the grid lines. DashList is a list of up to 11 numbers that alternately
represent the lengths of the dashes and gaps on the grid lines. Each number
must be between 1 and 255. If dashList is "", the grid will be solid lines.
- -hide boolean
- Indicates whether the grid should be drawn. If boolean is true,
grid lines are not shown. The default is yes.
- -linewidth pixels
- Sets the
width of grid lines. The default width is 1.
- -mapx xAxis
- Specifies the
X-axis to display grid lines. XAxis must be the name of an axis or ""
for no grid lines. The default is "".
- -mapy yAxis
- Specifies the Y-axis
to display grid lines. YAxis must be the name of an axis or "" for no
grid lines. The default is y.
- -minor boolean
- Indicates whether the grid
lines should be drawn for minor ticks. If boolean is true, the lines will
appear at minor tick intervals. The default is 1.
Grid configuration options
may also be set by the option command. The resource name and class are
grid and Grid respectively.
option add *Graph.grid.LineWidth 2
option add *Graph.Grid.Color black
-raised boolean
Grid is to be raised or drawn over elements.
- pathName grid
off
- Turns off the display the grid lines.
- pathName grid on
- Turns on the
display the grid lines.
- pathName grid toggle
- Toggles the display of the
grid.
The legend displays a list of the data elements.
Each entry consists of the element's symbol and label. The legend can appear
in any margin (the default location is in the right margin). It can also
be positioned anywhere within the plotting area.
The following operations
are valid for the legend.
- pathName legend activate pattern...
- Selects legend
entries to be drawn using the active legend colors and relief. All entries
whose element names match pattern are selected. To be selected, the element
name must match only one pattern.
- pathName legend bind tagName ?sequence?
?command?
- Associates command with tagName such that whenever the event
sequence given by sequence occurs for a legend entry with this tag, command
will be invoked. Implicitly the element names in the entry are tags. The
syntax is similar to the bind command except that it operates on legend
entries, rather than widgets. See the bind manual entry for complete details
on sequence and the substitutions performed on command before invoking
it.
If all arguments are specified then a new binding is created, replacing
any existing binding for the same sequence and tagName. If the first character
of command is + then command augments an existing binding rather than
replacing it. If no command argument is provided then the command currently
associated with tagName and sequence (it's an error occurs if there's no
such binding) is returned. If both command and sequence are missing then
a list of all the event sequences for which bindings have been defined
for tagName.
- pathName legend cget option
- Returns the current value of a
legend configuration option. Option may be any option described below in
the legend configure operation.
- pathName legend configure ?option value?...
- Queries or modifies the configuration options for the legend. If option
isn't specified, a list describing the current legend options for pathName
is returned. If option is specified, but not value, then a list describing
option is returned. If one or more option and value pairs are specified,
then for each pair, the legend option option is set to value. The following
options are valid for the legend.
- -activebackground color
- Sets the background
color for active legend entries. All legend entries marked active (see
the legend activate operation) are drawn using this background color.
- -activeborderwidth
pixels
- Sets the width of the 3-D border around the outside edge of the active
legend entries. The default is 2.
- -activeforeground color
- Sets the foreground
color for active legend entries. All legend entries marked as active (see
the legend activate operation) are drawn using this foreground color.
- -activerelief
relief
- Specifies the 3-D effect desired for active legend entries. Relief
denotes how the interior of the entry should appear relative to the legend;
for example, raised means the entry should appear to protrude from the
legend, relative to the surface of the legend. The default is flat.
- -anchor
anchor
- Tells how to position the legend relative to the positioning point
for the legend. This is dependent on the value of the -position option.
The default is center.
- left or right
- The anchor describes how to position
the legend vertically.
- top or bottom
- The anchor describes how to position
the legend horizontally.
- @x,y
- The anchor specifies how to position the
legend relative to the positioning point. For example, if anchor is center
then the legend is centered on the point; if anchor is n then the legend
will be drawn such that the top center point of the rectangular region
occupied by the legend will be at the positioning point.
- plotarea
- The
anchor specifies how to position the legend relative to the plotting area.
For example, if anchor is center then the legend is centered in the plotting
area; if anchor is ne then the legend will be drawn such that occupies
the upper right corner of the plotting area.
- -background color
- Sets the background
color of the legend. If color is "", the legend background with be transparent.
- -bindtags tagList
- Specifies the binding tags for legend entries. TagList
is a list of binding tag names. The tags and their order will determine
how events are handled for legend entries. Each tag in the list matching
the current event sequence will have its Tcl command executed. The default
value is all.
- -borderwidth pixels
- Sets the width of the 3-D border around
the outside edge of the legend (if such border is being drawn; the relief
option determines this). The default is 2 pixels.
- -font fontName
- FontName
specifies a font to use when drawing the labels of each element into the
legend. The default is *-Helvetica-Bold-R-Normal-*-12-120-*.
- -foreground color
- Sets the foreground color of the text drawn for the element's label. The
default is black.
- -hide boolean
- Indicates whether the legend should be
displayed. If boolean is true, the legend will not be draw. The default
is no.
- -ipadx pad
- Sets the amount of internal padding to be added to the
width of each legend entry. Pad can be a list of one or two screen distances.
If pad has two elements, the left side of the legend entry is padded by
the first distance and the right side by the second. If pad is just one
distance, both the left and right sides are padded evenly. The default
is 2.
- -ipady pad
- Sets an amount of internal padding to be added to the
height of each legend entry. Pad can be a list of one or two screen distances.
If pad has two elements, the top of the entry is padded by the first distance
and the bottom by the second. If pad is just one distance, both the top
and bottom of the entry are padded evenly. The default is 2.
- -padx pad
- Sets
the padding to the left and right exteriors of the legend. Pad can be a
list of one or two screen distances. If pad has two elements, the left
side of the legend is padded by the first distance and the right side by
the second. If pad has just one distance, both the left and right sides
are padded evenly. The default is 4.
- -pady pad
- Sets the padding above and
below the legend. Pad can be a list of one or two screen distances. If
pad has two elements, the area above the legend is padded by the first
distance and the area below by the second. If pad is just one distance,
both the top and bottom areas are padded evenly. The default is 0.
- -position
pos
- Specifies where the legend is drawn. The -anchor option also affects
where the legend is positioned. If pos is left, left, top, or bottom,
the legend is drawn in the specified margin. If pos is plotarea, then
the legend is drawn inside the plotting area at a particular anchor. If
pos is in the form "@x,y", where x and y are the window coordinates, the
legend is drawn in the plotting area at the specified coordinates. The
default is right.
- -raised boolean
- Indicates whether the legend is above
or below the data elements. This matters only if the legend is in the plotting
area. If boolean is true, the legend will be drawn on top of any elements
that may overlap it. The default is no.
- -relief relief
- Specifies the 3-D
effect for the border around the legend. Relief specifies how the interior
of the legend should appear relative to the graph; for example, raised
means the legend should appear to protrude from the graph, relative to
the surface of the graph. The default is sunken.
Legend configuration
options may also be set by the option command. The resource name and class
are legend and Legend respectively.
option add *Graph.legend.Foreground blue
option add *Graph.Legend.Relief raised
pathName legend deactivate pattern...
Selects legend entries to be drawn using
the normal legend colors and relief. All entries whose element names match
pattern are selected. To be selected, the element name must match only
one pattern.
pathName legend get pos
Returns the name of the element whose
entry is at the screen position pos in the legend. Pos must be in the form
"@x,y", where x and y are window coordinates. If the given coordinates
do not lie over a legend entry, "" is returned.
Pens define
attributes (both symbol and line style) for elements. Pens mirror the configuration
options of data elements that pertain to how symbols and lines are drawn.
Data elements use pens to determine how they are drawn. A data element
may use several pens at once. In this case, the pen used for a particular
data point is determined from each element's weight vector (see the element's
-weight and -style options).
One pen, called activeLine, is automatically
created. It's used as the default active pen for elements. So you can change
the active attributes for all elements by simply reconfiguring this pen.
.g pen configure "activeLine" -color green
You can create and use several pens. To create a pen, invoke the pen component
and its create operation.
.g pen create myPen
You map pens to a data element using either the element's -pen or -activepen
options.
.g element create "line1" -xdata $x -ydata $tempData \
-pen myPen
An element can use several pens at once. This is done by specifying the
name of the pen in the element's style list (see the -styles option).
.g element configure "line1" -styles { myPen 2.0 3.0 }
This says that any data point with a weight between 2.0 and 3.0 is to be
drawn using the pen myPen. All other points are drawn with the element's
default attributes.
The following operations are available for pen components.
- pathName pen cget penName option
- Returns the current value of the option
given by option for penName. Option may be any option described below for
the pen configure operation.
- pathName pen configure penName ?penName... ?option
value?...
- Queries or modifies the configuration options of penName. Several
pens can be modified at once. If option isn't specified, a list describing
the current options for penName is returned. If option is specified, but
not value, then a list describing option is returned. If one or more option
and value pairs are specified, then for each pair, the pen option option
is set to value. The following options are valid for pens.
- -color color
- Sets the color of the traces connecting the data points.
- -dashes dashList
- Sets the dash style of element line. DashList is a list of up to 11 numbers
that alternately represent the lengths of the dashes and gaps on the element
line. Each number must be between 1 and 255. If dashList is "", the lines
will be solid.
- -fill color
- Sets the interior color of symbols. If color
is "", then the interior of the symbol is transparent. If color is defcolor,
then the color will be the same as the -color option. The default is defcolor.
- -linewidth pixels
- Sets the width of the connecting lines between data points.
If pixels is 0, no connecting lines will be drawn between symbols. The
default is 0.
- -offdash color
- Sets the color of the stripes when traces
are dashed (see the -dashes option). If color is "", then the "off" pixels
will represent gaps instead of stripes. If color is defcolor, then the
color will be the same as the -color option. The default is defcolor.
- -outline
color
- Sets the color or the outline around each symbol. If color is "",
then no outline is drawn. If color is defcolor, then the color will be
the same as the -color option. The default is defcolor.
- -outlinewidth pixels
- Sets the width of the outline bordering each symbol. If pixels is 0,
no outline will be drawn. The default is 1.
- -pixels pixels
- Sets the size
of symbols. If pixels is 0, no symbols will be drawn. The default is
0.125i.
- -symbol symbol
- Specifies the symbol for data points. Symbol can
be either square, circle, diamond, plus, cross, splus, scross,
triangle, "" (where no symbol is drawn), or a bitmap. Bitmaps are specified
as "source ?mask?", where source is the name of the bitmap, and mask is
the bitmap's optional mask. The default is circle.
- -type elemType
- Specifies
the type of element the pen is to be used with. This option should only
be employed when creating the pen. This is for those that wish to mix different
types of elements (bars and lines) on the same graph. The default type
is "line".
Pen configuration options may be also be set by the option command.
The resource class is Pen. The resource names are the names of the pens.
option add *Graph.Pen.Color blue
option add *Graph.activeLine.color green
pathName pen create penName ?option value?...
Creates a new pen by the name
penName. No pen by the same name can already exist. Option and value are
described in above in the pen configure operation.
pathName pen delete
?penName?...
Deletes the named pens. A pen is not really deleted until it is
not longer in use, so it's safe to delete pens mapped to elements.
pathName
pen names ?pattern?...
Returns a list of pens matching zero or more patterns.
If no pattern argument is give, the names of all pens are returned.
The graph can generate encapsulated PostScript output. There are
several configuration options you can specify to control how the plot will
be generated. You can change the page dimensions and borders. The plot
itself can be scaled, centered, or rotated to landscape. The PostScript
output can be written directly to a file or returned through the interpreter.
The following postscript operations are available.
- pathName postscript cget
option
- Returns the current value of the postscript option given by option.
Option may be any option described below for the postscript configure
operation.
- pathName postscript configure ?option value?...
- Queries or modifies
the configuration options for PostScript generation. If option isn't specified,
a list describing the current postscript options for pathName is returned.
If option is specified, but not value, then a list describing option is
returned. If one or more option and value pairs are specified, then for
each pair, the postscript option option is set to value. The following
postscript options are available.
- -center boolean
- Indicates whether the plot
should be centered on the PostScript page. If boolean is false, the plot
will be placed in the upper left corner of the page. The default is 1.
- -colormap varName
- VarName must be the name of a global array variable that
specifies a color mapping from the X color name to PostScript. Each element
of varName must consist of PostScript code to set a particular color value
(e.g. ``1.0 1.0 0.0 setrgbcolor''). When generating color information in PostScript,
the array variable varName is checked if an element of the name as the
color exists. If so, it uses its value as the PostScript command to set
the color. If this option hasn't been specified, or if there isn't an entry
in varName for a given color, then it uses the red, green, and blue intensities
from the X color.
- -colormode mode
- Specifies how to output color information.
Mode must be either color (for full color output), gray (convert all
colors to their gray-scale equivalents) or mono (convert foreground colors
to black and background colors to white). The default mode is color.
- -fontmap varName
- VarName must be the name of a global array variable that
specifies a font mapping from the X font name to PostScript. Each element
of varName must consist of a Tcl list with one or two elements; the name
and point size of a PostScript font. When outputting PostScript commands
for a particular font, the array variable varName is checked to see if
an element by the specified font exists. If there is such an element,
then the font information contained in that element is used in the PostScript
output. (If the point size is omitted from the list, the point size of
the X font is used). Otherwise the X font is examined in an attempt to
guess what PostScript font to use. This works only for fonts whose foundry
property is Adobe (such as Times, Helvetica, Courier, etc.). If all of this
fails then the font defaults to Helvetica-Bold.
- -decorations boolean
- Indicates
whether PostScript commands to generate color backgrounds and 3-D borders
will be output. If boolean is false, the background will be white and
no 3-D borders will be generated. The default is 1.
- -height pixels
- Sets the
height of the plot. This lets you print the graph with a height different
from the one drawn on the screen. If pixels is 0, the height is the same
as the widget's height. The default is 0.
- -landscape boolean
- If boolean is
true, this specifies the printed area is to be rotated 90 degrees. In non-rotated
output the X-axis of the printed area runs along the short dimension of
the page (``portrait'' orientation); in rotated output the X-axis runs along
the long dimension of the page (``landscape'' orientation). Defaults to 0.
- -maxpect boolean
- Indicates to scale the plot so that it fills the PostScript
page. The aspect ratio of the graph is still retained. The default is 0.
- -padx pad
- Sets the horizontal padding for the left and right page borders.
The borders are exterior to the plot. Pad can be a list of one or two
screen distances. If pad has two elements, the left border is padded by
the first distance and the right border by the second. If pad has just
one distance, both the left and right borders are padded evenly. The default
is 1i.
- -pady pad
- Sets the vertical padding for the top and bottom page
borders. The borders are exterior to the plot. Pad can be a list of one
or two screen distances. If pad has two elements, the top border is padded
by the first distance and the bottom border by the second. If pad has just
one distance, both the top and bottom borders are padded evenly. The default
is 1i.
- -paperheight pixels
- Sets the height of the postscript page. This
can be used to select between different page sizes (letter, A4, etc). The
default height is 11.0i.
- -paperwidth pixels
- Sets the width of the postscript
page. This can be used to select between different page sizes (letter,
A4, etc). The default width is 8.5i.
- -width pixels
- Sets the width of the
plot. This lets you generate a plot of a width different from that of the
widget. If pixels is 0, the width is the same as the widget's width. The
default is 0.
Postscript configuration options may be also be set by the
option command. The resource name and class are postscript and Postscript
respectively.
option add *Graph.postscript.Decorations false
option add *Graph.Postscript.Landscape true
pathName postscript output ?fileName? ?option value?...
Outputs a file of
encapsulated PostScript. If a fileName argument isn't present, the command
returns the PostScript. If any option-value pairs are present, they set configuration
options controlling how the PostScript is generated. Option and value can
be anything accepted by the postscript configure operation above.
Markers are simple drawing procedures used to annotate or highlight
areas of the graph. Markers have various types: text strings, bitmaps,
images, connected lines, windows, or polygons. They can be associated with
a particular element, so that when the element is hidden or un-hidden, so
is the marker. By default, markers are the last items drawn, so that data
elements will appear in behind them. You can change this by configuring
the -under option.
Markers, in contrast to elements, don't affect the scaling
of the coordinate axes. They can also have elastic coordinates (specified
by -Inf and Inf respectively) that translate into the minimum or maximum
limit of the axis. For example, you can place a marker so it always remains
in the lower left corner of the plotting area, by using the coordinates
-Inf,-Inf.
The following operations are available for markers.
- pathName
marker after markerId ?afterId?
- Changes the order of the markers, drawing
the first marker after the second. If no second afterId argument is specified,
the marker is placed at the end of the display list. This command can be
used to control how markers are displayed since markers are drawn in the
order of this display list.
- pathName marker before markerId ?beforeId?
- Changes
the order of the markers, drawing the first marker before the second. If
no second beforeId argument is specified, the marker is placed at the beginning
of the display list. This command can be used to control how markers are
displayed since markers are drawn in the order of this display list.
- pathName
marker bind tagName ?sequence? ?command?
- Associates command with tagName
such that whenever the event sequence given by sequence occurs for a marker
with this tag, command will be invoked. The syntax is similar to the bind
command except that it operates on graph markers, rather than widgets.
See the bind manual entry for complete details on sequence and the substitutions
performed on command before invoking it.
If all arguments are specified
then a new binding is created, replacing any existing binding for the
same sequence and tagName. If the first character of command is + then
command augments an existing binding rather than replacing it. If no command
argument is provided then the command currently associated with tagName
and sequence (it's an error occurs if there's no such binding) is returned.
If both command and sequence are missing then a list of all the event
sequences for which bindings have been defined for tagName.
- pathName marker
cget option
- Returns the current value of the marker configuration option
given by option. Option may be any option described below in the configure
operation.
- pathName marker configure markerId ?option value?...
- Queries or
modifies the configuration options for markers. If option isn't specified,
a list describing the current options for markerId is returned. If option
is specified, but not value, then a list describing option is returned.
If one or more option and value pairs are specified, then for each pair,
the marker option option is set to value.
The following options are valid
for all markers. Each type of marker also has its own type-specific options.
They are described in the sections below.
- -bindtags tagList
- Specifies the
binding tags for the marker. TagList is a list of binding tag names. The
tags and their order will determine how events for markers are handled.
Each tag in the list matching the current event sequence will have its
Tcl command executed. Implicitly the name of the marker is always the
first tag in the list. The default value is all.
- -coords coordList
- Specifies
the coordinates of the marker. CoordList is a list of graph coordinates.
The number of coordinates required is dependent on the type of marker.
Text, image, and window markers need only two coordinates (an X-Y coordinate).
Bitmap markers can take either two or four coordinates (if four, they
represent the corners of the bitmap). Line markers need at least four coordinates,
polygons at least six. If coordList is "", the marker will not be displayed.
The default is "".
- -element elemName
- Links the marker with the element
elemName. The marker is drawn only if the element is also currently displayed
(see the element's show operation). If elemName is "", the marker is always
drawn. The default is "".
- -hide boolean
- Indicates whether the marker is
drawn. If boolean is true, the marker is not drawn. The default is no.
- -mapx xAxis
- Specifies the X-axis to map the marker's X-coordinates onto. XAxis
must the name of an axis. The default is x.
- -mapy yAxis
- Specifies the Y-axis
to map the marker's Y-coordinates onto. YAxis must the name of an axis. The
default is y.
- -name markerId
- Changes the identifier for the marker. The
identifier markerId can not already be used by another marker. If this
option isn't specified, the marker's name is uniquely generated.
- -under boolean
- Indicates whether the marker is drawn below/above data elements. If boolean
is true, the marker is be drawn underneath the data element symbols and
lines. Otherwise, the marker is drawn on top of the element. The default
is 0.
- -xoffset pixels
- Specifies a screen distance to offset the marker
horizontally. Pixels is a valid screen distance, such as 2 or 1.2i. The
default is 0.
- -yoffset pixels
- Specifies a screen distance to offset the
markers vertically. Pixels is a valid screen distance, such as 2 or 1.2i.
The default is 0.
Marker configuration options may also be set by the
option command. The resource class is either BitmapMarker, ImageMarker,
LineMarker, PolygonMarker, TextMarker, or WindowMarker, depending
on the type of marker. The resource name is the name of the marker.
option add *Graph.TextMarker.Foreground white
option add *Graph.BitmapMarker.Foreground white
option add *Graph.m1.Background blue
pathName marker create type ?option value?...
Creates a marker of the selected
type. Type may be either text, line, bitmap, image, polygon, or
window. This command returns the marker identifier, used as the markerId
argument in the other marker-related commands. If the -name option is used,
this overrides the normal marker identifier. If the name provided is already
used for another marker, the new marker will replace the old.
pathName marker
delete ?name?...
Removes one of more markers. The graph will automatically
be redrawn without the marker..
pathName marker exists markerId
Returns
1 if the marker markerId exists and 0 otherwise.
pathName marker names
?pattern?
Returns the names of all the markers that currently exist.
If pattern is supplied, only those markers whose names match it will be
returned.
pathName marker type markerId
Returns the type of the marker
given by markerId, such as line or text. If markerId is not a valid
a marker identifier, "" is returned.
A bitmap marker displays
a bitmap. The size of the bitmap is controlled by the number of coordinates
specified. If two coordinates, they specify the position of the top-left
corner of the bitmap. The bitmap retains its normal width and height. If
four coordinates, the first and second pairs of coordinates represent the
corners of the bitmap. The bitmap will be stretched or reduced as necessary
to fit into the bounding rectangle.
Bitmap markers are created with the
marker's create operation in the form:
pathName marker create bitmap ?option value?...
There may be many option-value pairs, each sets a configuration options
for the marker. These same option-value pairs may be used with the marker's
configure operation.
The following options are specific to bitmap markers:
- -background color
- Same as the -fill option.
- -bitmap bitmap
- Specifies the bitmap
to be displayed. If bitmap is "", the marker will not be displayed. The
default is "".
- -fill color
- Sets the background color of the bitmap. If
color is the empty string, no background will be transparent. The default
background color is "".
- -foreground color
- Same as the -outline option.
- -mask
mask
- Specifies a mask for the bitmap to be displayed. This mask is a bitmap
itself, denoting the pixels that are transparent. If mask is "", all
pixels of the bitmap will be drawn. The default is "".
- -outline color
- Sets
the foreground color of the bitmap. The default value is black.
- -rotate
theta
- Sets the rotation of the bitmap. Theta is a real number representing
the angle of rotation in degrees. The marker is first rotated and then
placed according to its anchor position. The default rotation is 0.0.
A image marker displays an image. Image markers are created with
the marker's create operation in the form:
pathName marker create image ?option value?...
There may be many option-value pairs, each sets a configuration option for
the marker. These same option-value pairs may be used with the marker's configure
operation.
The following options are specific to image markers:
- -anchor anchor
- Anchor tells how to position the image relative to the positioning point
for the image. For example, if anchor is center then the image is centered
on the point; if anchor is n then the image will be drawn such that
the top center point of the rectangular region occupied by the image will
be at the positioning point. This option defaults to center.
- -image image
- Specifies the image to be drawn. If image is "", the marker will not be
drawn. The default is "".
A line marker displays one or more
connected line segments. Line markers are created with marker's create operation
in the form:
pathName marker create line ?option value?...
There may be many option-value pairs, each sets a configuration option for
the marker. These same option-value pairs may be used with the marker's configure
operation.
The following options are specific to line markers:
- -dashes dashList
- Sets the dash style of the line. DashList is a list of up to 11 numbers
that alternately represent the lengths of the dashes and gaps on the line.
Each number must be between 1 and 255. If dashList is "", the marker
line will be solid.
- -fill color
- Sets the background color of the line. This
color is used with striped lines (see the -fdashes option). If color is the
empty string, no background color is drawn (the line will be dashed, not
striped). The default background color is "".
- -linewidth pixels
- Sets the
width of the lines. The default width is 0.
- -outline color
- Sets the foreground
color of the line. The default value is black.
- -stipple bitmap
- Specifies
a stipple pattern used to draw the line, rather than a solid line. Bitmap
specifies a bitmap to use as the stipple pattern. If bitmap is "", then
the line is drawn in a solid fashion. The default is "".
A
polygon marker displays a closed region described as two or more connected
line segments. It is assumed the first and last points are connected. Polygon
markers are created using the marker create operation in the form:
pathName marker create polygon ?option value?...
There may be many option-value pairs, each sets a configuration option for
the marker. These same option-value pairs may be used with the marker configure
command to change the marker's configuration. The following options are supported
for polygon markers:
- -dashes dashList
- Sets the dash style of the outline
of the polygon. DashList is a list of up to 11 numbers that alternately
represent the lengths of the dashes and gaps on the outline. Each number
must be between 1 and 255. If dashList is "", the outline will be a solid
line.
- -fill color
- Sets the fill color of the polygon. If color is "", then
the interior of the polygon is transparent. The default is white.
- -linewidth
pixels
- Sets the width of the outline of the polygon. If pixels is zero,
no outline is drawn. The default is 0.
- -outline color
- Sets the color of
the outline of the polygon. If the polygon is stippled (see the -stipple
option), then this represents the foreground color of the stipple. The
default is black.
- -stipple bitmap
- Specifies that the polygon should be
drawn with a stippled pattern rather than a solid color. Bitmap specifies
a bitmap to use as the stipple pattern. If bitmap is "", then the polygon
is filled with a solid color (if the -fill option is set). The default is
"".
A text marker displays a string of characters on one or
more lines of text. Embedded newlines cause line breaks. They may be used
to annotate regions of the graph. Text markers are created with the create
operation in the form:
pathName marker create text ?option value?...
There may be many option-value pairs, each sets a configuration option
for the text marker. These same option-value pairs may be used with the
marker's configure operation.
The following options are specific to text
markers:
- -anchor anchor
- Anchor tells how to position the text relative to
the positioning point for the text. For example, if anchor is center then
the text is centered on the point; if anchor is n then the text will
be drawn such that the top center point of the rectangular region occupied
by the text will be at the positioning point. This default is center.
- -background color
- Same as the -fill option.
- -font fontName
- Specifies the font
of the text. The default is *-Helvetica-Bold-R-Normal-*-120-*.
- -fill color
- Sets
the background color of the text. If color is the empty string, no background
will be transparent. The default background color is "".
- -foreground color
- Same as the -outline option.
- -justify justify
- Specifies how the text should
be justified. This matters only when the marker contains more than one
line of text. Justify must be left, right, or center. The default
is center.
- -outline color
- Sets the color of the text. The default value
is black.
- -padx pad
- Sets the padding to the left and right exteriors of
the text. Pad can be a list of one or two screen distances. If pad has two
elements, the left side of the text is padded by the first distance and
the right side by the second. If pad has just one distance, both the left
and right sides are padded evenly. The default is 4.
- -pady pad
- Sets the
padding above and below the text. Pad can be a list of one or two screen
distances. If pad has two elements, the area above the text is padded by
the first distance and the area below by the second. If pad is just one
distance, both the top and bottom areas are padded evenly. The default
is 4.
- -rotate theta
- Specifies the number of degrees to rotate the text.
Theta is a real number representing the angle of rotation. The marker
is first rotated along its center and is then drawn according to its anchor
position. The default is 0.0.
- -text text
- Specifies the text of the marker.
The exact way the text is displayed may be affected by other options such
as -anchor or -rotate.
A window marker displays a widget at
a given position. Window markers are created with the marker's create operation
in the form:
pathName marker create window ?option value?...
There may be many option-value pairs, each sets a configuration option for
the marker. These same option-value pairs may be used with the marker's configure
command.
The following options are specific to window markers:
- -anchor anchor
- Anchor tells how to position the widget relative to the positioning point
for the widget. For example, if anchor is center then the widget is centered
on the point; if anchor is n then the widget will be displayed such that
the top center point of the rectangular region occupied by the widget will
be at the positioning point. This option defaults to center.
- -height pixels
- Specifies the height to assign to the marker's window. If this option isn't
specified, or if it is specified as "", then the window is given whatever
height the widget requests internally.
- -width pixels
- Specifies the width
to assign to the marker's window. If this option isn't specified, or if it
is specified as "", then the window is given whatever width the widget
requests internally.
- -window pathName
- Specifies the widget to be managed
by the graph. PathName must be a child of the graph widget.
Specific graph components, such as elements, markers and legend
entries, can have a command trigger when event occurs in them, much like
canvas items in Tk's canvas widget. Not all event sequences are valid. The
only binding events that may be specified are those related to the mouse
and keyboard (such as Enter, Leave, ButtonPress, Motion, and KeyPress).
Only one element or marker can be picked during an event. This means, that
if the mouse is directly over both an element and a marker, only the uppermost
component is selected. This isn't true for legend entries. Both a legend
entry and an element (or marker) binding commands will be invoked if both
items are picked.
It is possible for multiple bindings to match a particular
event. This could occur, for example, if one binding is associated with
the element name and another is associated with one of the element's tags
(see the -bindtags option). When this occurs, all of the matching bindings
are invoked. A binding associated with the element name is invoked first,
followed by one binding for each of the element's bindtags. If there are
multiple matching bindings for a single tag, then only the most specific
binding is invoked. A continue command in a binding script terminates
that script, and a break command terminates that script and skips any
remaining scripts for the event, just as for the bind command.
The -bindtags
option for these components controls addition tag names which can be matched.
Implicitly elements and markers always have tags matching their names.
Setting the value of the -bindtags option doesn't change this.
You can manipulate data elements from the C language. There may be situations
where it is too expensive to translate the data values from ASCII strings.
Or you might want to read data in a special file format.
Data can manipulated
from the C language using BLT vectors. You specify the X-Y data coordinates
of an element as vectors and manipulate the vector from C. The graph will
be redrawn automatically after the vectors are updated.
From Tcl, create
the vectors and configure the element to use them.
vector X Y
.g element configure line1 -xdata X -ydata Y
To set data points from C, you pass the values as arrays of doubles using
the Blt_ResetVector call. The vector is reset with the new data and at
the next idle point (when Tk re-enters its event loop), the graph will be
redrawn automatically.
#include <tcl.h>
#include <blt.h>
register int i;
Blt_Vector *xVec, *yVec;
double x[50], y[50];
/* Get the BLT vectors "X" and "Y" (created above from Tcl) */
if ((Blt_GetVector(interp, "X", &xVec) != TCL_OK) ||
(Blt_GetVector(interp, "Y", &yVec) != TCL_OK)) {
return TCL_ERROR;
}
for (i = 0; i < 50; i++) {
x[i] = i * 0.02;
y[i] = sin(x[i]);
}
/* Put the data into BLT vectors */
if ((Blt_ResetVector(xVec, x, 50, 50, TCL_VOLATILE) != TCL_OK) ||
(Blt_ResetVector(yVec, y, 50, 50, TCL_VOLATILE) != TCL_OK)) {
return TCL_ERROR;
}
See the vector manual page for more details.
There may be cases
where the graph needs to be drawn and updated as quickly as possible. If
drawing speed becomes a big problem, here are a few tips to speed up displays.
- Try to minimize the number of data points. The more data points the looked
at, the more work the graph must do.
- If your data is generated as floating
point values, the time required to convert the data values to and from
ASCII strings can be significant, especially when there any many data points.
You can avoid the redundant string-to-decimal conversions using the C API
to BLT vectors.
- Data elements without symbols are drawn faster than with
symbols. Set the data element's -symbol option to none. If you need to draw
symbols, try using the simple symbols such as splus and scross.
- Don't
stipple or dash the element. Solid lines are much faster.
- If you update
data elements frequently, try turning off the widget's -bufferelements option.
When the graph is first displayed, it draws data elements into an internal
pixmap. The pixmap acts as a cache, so that when the graph needs to be
redrawn again, and the data elements or coordinate axes haven't changed,
the pixmap is simply copied to the screen. This is especially useful when
you are using markers to highlight points and regions on the graph. But
if the graph is updated frequently, changing either the element data or
coordinate axes, the buffering becomes redundant.
Auto-scale routines
do not use requested min/max limits as boundaries when the axis is logarithmically
scaled.
The PostScript output generated for polygons with more than 1500
points may exceed the limits of some printers (See PostScript Language
Reference Manual, page 568). The work-around is to break the polygon into
separate pieces.
graph, widget
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