Table of Contents
stripchart - 2D strip chart for plotting x and
y coordinate data.
stripchart pathName ?option value?...
The
stripchart command creates a strip chart 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 strip chart.
The stripchart is essentially the
same as the graph widget. It works almost exactly the very same way.
The
use of a strip chart differs in that the X-axis typically refers to time
points. Data values are added at intervals. The strip chart lets you automatically
maintain a view of the most recent time points. The axis options -shiftby
and -autorange control this. You can specify different line styles for data
points (see the -styles option).
The stripchart command creates
a new window for plotting two-dimensional data (x,y coordinates). Data points
are plotted in a box displayed in the center of the new window. This is
the plotting area. The coordinate axes are displayed in the margins around
the plotting area. By default, the legend is displayed in the right margin.
The title is displayed in top margin.
A strip chart is composed of several
components: coordinate axes, data elements, legend, grid, cross hairs,
pens, postscript, and annotation markers.
- axis
- The stripchart widget can
display up to four coordinate axes (two X-coordinate and two Y-coordinate
axes), but you can create and use 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 of each major tick.
- crosshairs
- Cross hairs are used to
finely position the mouse pointer in relation to the coordinate axes. Two
perpendicular lines are drawn across the plotting area, intersecting at
the current location of the mouse pointer.
- 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.
stripchart pathName ?option value?...
The stripchart command creates a new window pathName and makes it into
a stripchart 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 may be specified on the command line or in the option database
to configure aspects of the strip chart such as its colors and font. See
the configure operation below for the exact details as to what option and
value pairs are valid.
If successful, stripchart returns the path name of
the widget. It also creates a new Tcl command by the same name. You can
use this command to perform 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 strip chart are described in the STRIPCHART
OPERATIONS
section.
The command can also be used to access components of
the strip chart.
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 stripchart command creates a new strip chart.
# Create a new strip chart. Plotting area is black.
stripchart .s -plotbackground black
A new Tcl command .s is also created. This command can be used to query
and modify the strip chart. For example, to change the title of the strip
chart to "My Plot", you use the new command and the widget's configure operation.
# Change the title.
.s configure -title "My Plot"
A strip chart 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"
.s 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 and 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 strip chart.
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 }
.s element create line1 -xdata xVec -ydata yVec
The advantage of using vectors is that when you modify one, the graph is
automatically redrawn to display the new values.
# 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 .s. 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.
.s 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.
.s 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".
.s 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 operation.
# Y-axis is log scale.
.s axis configure y -logscale yes
Axis limits are reset by simply specifying new axis limits using the -min
and -max configuration options.
.s axis configure x -min 1.0 -max 1.5
.s axis configure y -min 12.0 -max 55.15
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.
.s axis configure x -min {} -max {}
.s axis configure y -min {} -max {}
It's common with strip charts to automatically maintain a view of the most
recent time points. You can do this my setting the -autorange option.
.s axis configure x -autorange 20.0
If the time points are added in X-coordinates 1.0 unit, only the last twenty
time points will be displayed. As more data is added, the view will march
along.
Sometimes the rate of data is so high that changing the axis limits
with each additional time point is prohibitive. You can use the -shiftby
option to define an increment to shift the view when needed.
.s axis configure x -shiftby 15.0
When the view is shifted, it will allow a range of 15 new time points to
be added until the axis limits are recomputed.
By default, the legend is
displayed in the right margin. You can change this or any other legend
configuration options using the legend component.
# Configure the legend font, color, and relief
.s 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.
.s legend configure -hide yes
The stripchart widget has simple drawing procedures called markers. They
can be used to highlight or annotate data in the strip chart. The types
of markers available are bitmaps, images, polygons, lines, or windows. Markers
can be used, for example, to mark or brush points. Here is a text marker
which labels the data first point. Markers are created using the marker
operation.
# Create a label for the first data point of "line1".
.s 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 actual 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.
.s marker configure first_marker -under yes
You can add cross hairs or grid lines using the crosshairs and grid operations.
# Display both cross hairs and grid lines.
.s crosshairs configure -hide no -color red
.s grid configure -hide no -dashes { 2 2 }
Finally, to get hardcopy of the strip chart, use the postscript operation.
# Print the strip chart into file "file.ps"
.s postscript output file.ps -maxpect yes -decorations no
This generates a file file.ps containing the encapsulated PostScript of
the strip chart. The option -maxpect says to scale the plot to the size
of the page. Turning off the -decorations option indicates that no borders
or color backgrounds should be displayed (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 stripchart 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 strip chart. If option isn't specified, a list describing all of
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 stripchart option
option is set to value. The following options are valid for the stripchart.
- -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
- Specifies the size of the margin below the X-coordinate axis. If
pixels is 0, the size of the margin is selected automatically. The default
is 0.
- -bufferelements boolean
- Indicates whether to draw elements into a pixmap
before displaying them on the screen. The advantage of buffering elements
is when markers are used heavily. Markers can be moved and redrawn without
requiring every element to be redrawn again. The disadvantage is that it
takes slightly longer to draw the graph. If boolean is true, data elements
are drawn to an internal pixmap. The option should be turned off if the
plot is updated frequently. See the SPEED TIPS
section. The default is 1.
- -buffergraph boolean
- Indicates whether to draw the graph into a pixmap first.
If boolean is true, the entire graph is drawn into a pixmap and then copied
onto the screen. This reduces flashing. If false, the graph is drawn directly
into the window. Especially under Windows, turning off the option can
be helpful when the stripchart is updated frequently. Turning off this
option also turns -bufferelements off. 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 title font. 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
- Sets the size
of the margin from the left edge of the window to the Y-coordinate axis.
If pixels is 0, the size is calculated automatically. 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 indicates how the interior of the plotting
area should appear relative to rest of the strip chart; for example, raised
means the plot should appear to protrude from the strip chart, relative
to the surface of the strip chart. The default is sunken.
- -relief relief
- Specifies the 3-D effect for the widget. Relief indicates how the strip
chart should appear relative to widget it is packed into; for example,
raised means the strip chart should appear to protrude. The default is
flat.
- -rightmargin pixels
- Sets the size of margin from the plotting area
to the right edge of the window. By default, the legend is displayed in
this margin. If pixels is than 1, the margin size is selected automatically.
- -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. 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
- Specifies the size of the margin above the x2
axis. If pixels is 0, the margin size is calculated automatically.
- -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 strip chart. 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 graph coordinates.
- pathName
legend operation ?arg?...
- See the LEGEND COMPONENT
section.
- pathName line
elemName ?option value?...
- The operation is the same as element.
- pathName marker
operation ?arg?...
- See the MARKER COMPONENTS
section.
- pathName metafile ?fileName?
- This operation is for Window platforms only. Creates a Windows enhanced
metafile of the stripchart. If present, fileName is the file name of the
new metafile. Otherwise, the metafile is automatically added to the clipboard.
- pathName postscript operation ?arg?...
- See the POSTSCRIPT COMPONENT
section.
- pathName snap photoName
- Takes a snapshot of the strip chart and stores
the contents in the photo image photoName. PhotoName is the name of a Tk
photo image that must already exist.
- 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 strip chart 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 strip chart is partitioned, where each component
has its own configuration options and operations that specifically control
that aspect or part of the strip chart.
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 create and use several axes. To create an axis, invoke the axis component
and its create operation.
# Create a new axis called "temperature"
.s axis create temperature
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 temperature data to this axis.
.s element create "temp" -xdata $x -ydata $tempData \
-mapy temperature
While you can have many axes, only four axes can be displayed simultaneously.
They are drawn in each of the margins surrounding the plotting area. The
axes x and y are drawn in the bottom and left margins. The axes x2 and y2
are drawn in top and right margins. Only x and y are shown by default. Note
that the axes can have different scales.
To display a different axis, you
invoke one of the following components: xaxis, yaxis, x2axis, and y2axis.
The use operation designates the axis to be drawn in the corresponding
margin: xaxis in the bottom, yaxis in the left, x2axis in the top, and
y2axis in the right.
# Display the axis temperature in the left margin.
.s yaxis use temperature
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 as 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 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 ?option value?...
- Queries or modifies the
configuration options of axisName. 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.
- -autorange
range
- Sets the range of values for the axis to range. The axis limits
are automatically reset to display the most recent data points in this
range. If range is 0.0, the range is determined from the limits of the
data. If -min or -max are specified, they override this option. The default
is 0.0.
- -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 strip chart is redrawn. You may query the
configuration options. But do not reset 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 whether
the axis is displayed.
- -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. This is
relevant only when the axis limit is automatically calculated. 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.
- -shiftby
value
- Specifies how much to automatically shift the range of the axis. When
the new data exceeds the current axis maximum, the maximum is increased
in increments of value. You can use this option to prevent the axis limits
from being recomputed at each new time point. If value is 0.0, then no automatic
shifting is done. The default is 0.0.
- -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.
- -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 *Stripchart.Axis.Color blue
option add *Stripchart.x.LogScale true
option add *Stripchart.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.
Only four axes can be displayed
simultaneously. By default, they are x, y, x2, and y2. You can 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. The xaxis
component manages the X-axis located in the bottom margin (whatever axis
that happens to be). Likewise, yaxis uses the Y-axis in the left margin,
x2axis the top X-axis, and y2axis the right Y-axis.
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. These components
can be more convenient to use than always determining what axes are current
being displayed by the graph.
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.
- 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
strip chart.
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 *Stripchart.Crosshairs.LineWidth 2
option add *Stripchart.Crosshairs.Color red
pathName crosshairs off
Turns of 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 cget elemName
option
- Returns the current value of the element configuration option given
by option. Option may be any option described below for the element configure
operation.
- pathName element closest x y varName ?option value?... ?elemName?...
- Finds the data point closest to the window coordinates x and y in the element
elemName. ElemName is the name of an element, that must not be hidden.
If no elements are specified, then all visible elements are searched. It
returns via the array variable varName the name of the closest element,
the index of its closest 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.
- -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 stripchart's -halo option.
- -interpolate boolean
- Indicates that both the data points and interpolated
points along the line segment formed should be considered. If boolean
is true, the closest line segment will be selected instead of the closest
point. If this option isn't specified, boolean defaults to 0.
- pathName element
configure elemName ?option value?...
- Queries or modifies the configuration
options for elements. 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.
- -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.
- -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 which 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 upon 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 number of the pen in the list.
- -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.
- -weights wVec
- Specifies the weights of the individual
data points. This, in conjunction 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 *Stripchart.Element.symbol line
option add *Stripchart.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 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. The default is x.
- -mapy yAxis
- Specifies the Y-axis to display grid lines. YAxis must be the
name of an axis. 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 *Stripchart.grid.LineWidth 2
option add *Stripchart.Grid.Color black
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 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.
- -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 strip chart; for example, raised means
the legend should appear to protrude from the strip chart, relative to
the surface of the strip chart. 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 *Stripchart.legend.Foreground blue
option add *Stripchart.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.
.s pen configure "activeLine" -color green
You can create and use any number of pens. To create a pen, invoke the pen
component and its create operation.
.s pen create myPen
You map pens to a data element using either the element's -pen or -activepen
options.
.s 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).
.s 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 ?option value?...
- Queries or modifies the configuration options of penName. 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 *Stripchart.Pen.Color blue
option add *Stripchart.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 strip chart can generate encapsulated PostScript output. There
are several configuration options you can specify to control how the plot
is 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 outputting color information in PostScript, the
array variable varName is checked to see if an element of the name of
the color exists. If so, it uses the value of the element 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, which are
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 an element of 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
if PostScript commands to generate color backgrounds and 3-D borders should
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 plot the stripchart with a height different
from the one displayed on the screen. If pixels is 0, the height is the
same as the displayed 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 the plot so that it fills the PostScript
page. The aspect ratio of the strip chart 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 plot the
strip chart with a width different from the one drawn on the screen. 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 *Stripchart.postscript.Decorations false
option add *Stripchart.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 strip chart. 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 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.
- -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 *Stripchart.TextMarker.Foreground white
option add *Stripchart.BitmapMarker.Foreground white
option add *Stripchart.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
- Sets the background color of the bitmap. If color is "",
the background color will be transparent. The default background color
is white.
- -bitmap bitmap
- Specifies the bitmap to be displayed. If bitmap
is "", the marker will not be displayed. The default is "".
- -foreground color
- Sets the foreground color of the bitmap. The default foreground color
is black.
- -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 "".
- -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:
- -background
color
- Sets the background color of the line. The option is affects the line
color only when the -stipple option is set. If this option isn't specified
then it defaults to white.
- -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.
- -foreground color
- Sets
the foreground color. The default foreground color is black.
- -linewidth pixels
- Sets the width of the lines. The default width is 0.
- -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 strip chart. 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
- Sets the background color of the text string. If color is "", the
background will be transparent. The default is white.
- -font fontName
- Specifies
the font of the text. The default is *-Helvetica-Bold-R-Normal-*-120-*.
- -foreground
color
- Sets the foreground color of the text. The default is black.
- -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.
- -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.
PathName must be a child of the stripchart widget.
Specific
stripchart 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 -bindtagsR 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 and y data coordinates of
an element as vectors and manipulate the vector from C. The strip chart
will be redrawn automatically after the vectors are updated.
From Tcl, create
the vectors and configure the element to use them.
vector X Y
.s 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 strip chart
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", 50, &xVec) != TCL_OK) ||
(Blt_GetVector(interp, "Y", 50, &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 strip chart 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 strip chart 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 strip chart is first displayed, it draws data elements
into an internal pixmap. The pixmap acts as a cache, so that when the strip
chart 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
strip chart. But if the strip chart 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.
The -mapped options
are obsoleted and will be removed. You can achieve the same results using
the -hide option instead.
# Works for now.
.s legend configure -mapped no
# Instead use this.
.s legend configure -hide yes
Keywords
stripchart, graph, widget
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