#toc
Table of Contents
#toc0
Name
stripchart -  2D strip chart for plotting x and
y coordinate data.
#toc1
Synopsis
stripchart
pathName
?
option value
?...
#toc2
Description
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).
#toc3
Introduction
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.
#toc4
Syntax
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.
#toc5
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).
#toc6
Stripchart Operations
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.
#toc7
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.
#toc8
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.
#toc9
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.
#toc10
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"
.
#toc11
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.
#toc12
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.
#toc13
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.
.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.
#toc14
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.
#toc15
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.
#toc16
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
.
#toc17
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
""
.
#toc18
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
""
.
#toc19
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
""
.
#toc20
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
.
#toc21
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.
#toc22
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
-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.
#toc23
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.
#toc24
Speed Tips
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.
#toc25
Limitations
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.
#toc26
Future Incompatibility
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
#toc27
Keywords
stripchart, graph, widget
Table of Contents
#sect0
Name
#sect1
Synopsis
#sect2
Description
#sect3
Introduction
#sect4
Syntax
#sect5
Example
#sect6
Stripchart Operations
#sect7
Stripchart Components
#sect8
Axis Components
#sect9
Crosshairs Component
#sect10
Element Components
#sect11
Grid Component
#sect12
Legend Component
#sect13
Pen Components
#sect14
PostScript Component
#sect15
Marker Components
#sect16
Bitmap Markers
#sect17
Image Markers
#sect18
Line Markers
#sect19
Polygon Markers
#sect20
Text Markers
#sect21
Window Markers
#sect22
Graph Component Bindings
#sect23
C Language API
#sect24
Speed Tips
#sect25
Limitations
#sect26
Future Incompatibility
#sect27
Keywords
