EXAMPLE
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).
STRIPCHART COMPONENTS
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.
AXIS COMPONENTS
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.
CROSSHAIRS COMPONENT
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.
ELEMENT COMPONENTS
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 COMPONENT
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.
LEGEND COMPONENT
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.
PEN COMPONENTS
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.
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.
POSTSCRIPT COMPONENT
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.
MARKER COMPONENTS
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.
BITMAP MARKERS
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.
IMAGE MARKERS
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 "".
LINE MARKERS
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 "".
POLYGON MARKERS
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 "".
TEXT MARKERS
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.
WINDOW MARKERS
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.
GRAPH COMPONENT BINDINGS
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
-bindtagsfor 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.
C LANGUAGE API
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.