graph input
input
List of operands to be graphed. May be STDIN, or one or more image sections
or lists.
wx1=0., wx2=0., wy1=0., wy2=0.
The range of user coordinates spanned by the plot. If the range of values
in x or y = 0, the plot is automatically scaled from the minimum to
maximum data value along the degenerate dimension.
wcs = logical
The world coordinate system (wcs) to be used for axis labeling when
input is f rom images.
The following standard world systems are predefined.
logical
Logical coordinates are image pixel coordinates relative to the image currently
being displayed.
physical
The physical coordinate system is invariant with respect to linear
transformations of the physical image matrix. For example, if the reference
image was created by extracting a section of another image, the physical
coordinates of an object in the reference image will be the pixel coordinates
of the same object in the original image. The physical coordinate system
thus provides a consistent coordinate system (a given object always has the
same coordinates) for all images, regardless of whether any user world
coordinate systems have been defined.
world
The "world" coordinate system is the current default WCS.
The default world system is the system named by the environment variable
defwcs if defined in the user environment and present in the reference
image WCS description, else it is the first user WCS defined for the image
(if any), else physical coordinates are returned.
In addition to these three reserved WCS names, the name of any user WCS defined for the reference image may be given. A user world coordinate system may be any linear or nonlinear world system.
vx1=0., vx2=0., vy1=0., vy2=0.
NDC coordinates (0-1) of the device plotting viewport. If not set by
the user, a suitable viewport which allows sufficient room for all labels
is used.
pointmode = no
If pointmode = yes, plot points or markers at data values, rather than
connected lines.
marker = box
Marker to be drawn if pointmode = yes. Markers are "point", "box",
"cross", "plus", "circle", "hebar", "vebar", "hline", "vline" or "diamond".
szmarker = 0.005
The size of a marker in NDC coordinates (0 to 1 spans the screen).
If zero and the input operand is a list, marker sizes are taken individually
from the third column of each list element. If positive, all markers are
of size szmarker. If negative and the input operand is a list,
the size of a marker is the third column of each list element times the
absolute value of szmarker.
xlabel = wcslabel , ylabel =
Label for the X-axis or Y-axis. if xlabel = "wcslabel" and the first
operand in the input is an image, the world coordinate system label
if defined is used.
title = imtitle
Plot title. If title = "imtitle"
and the first operand in input is an image, the image title is used
as the plot title.
xformat = wcsformat , yformat =
The numerical format for the coordinate labels. The values may be ""
(an empty string), %f for decimal format, %h and %H for xx:xx:xx format, and
%m and %M for xx:xx.x format. The upper case %H and %M convert degrees
to hours. For images a recommended x coordinate format may be defined as
a WCS attribute. If the xformat value is "wcsformat" the WCS attribute
format will be used. Any other value will override the image attribute.
box = yes
Draw axes at the perimeter of the plotting window.
fill = yes
Fill the output viewport regardless of the device aspect ratio?
axis = 1
Axis along which the projection is to be computed, if an input operand is
an image section of dimension 2 or higher. Axis 1 is X (line average),
2 is Y (column average), and so on.
transpose = no
Swap the X and Y axes of the plot. If enabled, the axes are transposed
after the optional linear transformation of the X-axis.
logx = no, logy = no
Log scale the X or Y axis. Zero or negative values are indefinite and
will not be plotted, but are tolerated.
ticklabels = yes
Label the tick marks.
majrx=5, minrx=5, majry=5, minry=5
Number of major tick marks on each axis; number of minor tick marks between
major tick marks. Ignored if log scaling is in effect for an axis.
lintran = no
Perform a linear transformation of the X-axis upon input. Used to assign
logical coordinates to the indices of pixel data arrays (image sections).
p1=0, p2=0, q1=0, q2=1
If lintran is enabled, pixel index P1 is mapped to Q1, and P2 to Q2.
If P1 and P2 are zero, P1 is set to 1 and P2 to the number of pixels in
the input array.
round = no
Extend the axes up to "nice" values.
overplot = no
Overplot on an existing plot. All axis scaling and labeling parameters
apply.
append = no
Append to an existing plot. The previous axis is used and the axis
scaling and labeling parameters are ignored.
device = stdgraph
The output device.
Graph graphs one or more lists or image sections; lists and image sections may be mixed in the input list at will. If the curves are not all the same length the plot will be scaled to the longest curve and all curves will be plotted left justified. If an image section operand has more than one dimension the projection (average) along a designated axis will be computed and plotted. By default, a unique dash pattern is used for each curve, up to a maximum of 4.
List input may be taken from the standard input or from a file, and consists of a sequence of Y values, X and Y values, or X, Y, and marker size values, one pair of coordinates per line in the list. If the third column of a list contains positive numbers, they are interpreted as NDC marker sizes, optionally scaled by the absolute value of szmarker. If you want the third column of a list to be interpreted as WCS coordinates, indicating errors for example, the marker sizes should be entered as negative numbers. Blank lines, comment lines, and extra columns are ignored. The first element in the list determines whether the list is a Y list or and X,Y list; it is an error if an X,Y list has fewer than two coordinates in any element. INDEF valued elements appear as gaps in the plot.
If append is enabled, previous values for box, fill, round, the plotting viewport (vx1, vx2, vy1, vy2), and the plotting window (wx1, wx2, wy1, wy2) are used. The overplot parameter overplots a new plot including any new axis scaling and labeling.
By default, the plot drawn will fill the device viewport, if the viewport was either specified by the user or automatically calculated by graph. Setting the value of fill to "no" means the viewport will be adjusted so that equal numbers of data values in x and y will occupy equal lengths when plotted. That is, when fill = no, a unity aspect ratio is enforced, and plots appear square regardless of the device aspect ratio. On devices with non square full device viewports (e.g., the vt640), a plot drawn by graph appears extended in the x direction unless fill = no.
1. Plot the output of a list processing filter:
cl> ... list_filter | graph
2. Plot a graph entered interactively from the terminal:
cl> graph STDIN
3. Overplot two lists:
cl> graph list1,list2
4. Graph line 128 of image "pix":
cl> graph pix[*,128]
5. Graph the average of columns 50 through 100:
cl> graph pix[50:100,*] axis=2
6. Graph a list in point plot mode:
cl> graph list po+
7. Annotate a graph:
cl> graph pix[*,10],pix[*,20] xlabel=column
>>> ylabel=intensity title="lines 10 and 20 of pix"
8. Direct the graph to the standard plotter device:
cl> graph list device=stdplot
Indefinites are not recognized when computing image projections.