Plotting

DPUSER incorporates the complete PGPLOT package. All modules of this package are realized as procedures (see list of available PGPLOT procedures). The PGPLOT documentation provided here is a verbatim copy of the online documentation of PGPLOT.
DPUSER uses a global variable plotdevice to control graphics output. Available devices depend on your installation of PGPLOT. The default graphics device on UNIX workstations is "/xserve". This can be changed by assigning a new string value to the variable. A typical use of PGPLOT looks like this:

plotdevice = "/tmp/test.eps/ps"      // Write ps output to /tmp/test.eps
x = [-3600:3600]/10                  // create x-axes
y = sin(x, /deg)                     // create sine function (y-axes)
pgopen plotdevice                    // Start plotting
pgenv -360, 360, -1, 1, 0, 0         // draw labeled frame
pglab "angle", "sine", "test plot"   // annotate plot
pgline 7201, x, y                    // draw the sine function
pgend                                // end plotting
plotdevice = "/xserve"               // reset graph output to X
Since plotting a x-y graph is, amongs others, a very common task, DPUSER provides several convenience procedures to do things like this: plot, contour, surface, and shade. The above example using the plot command looks like this:
plotdevice = "/tmp/test.eps/ps"      // Write ps output to /tmp/test.eps
x = [-3600:3600]/10                  // create x-axes
y = sin(x, /deg)                     // create sine function (y-axes)
plot x, y, xtitle="angle", ytitle="sine", title="test plot"
                                     // do the plot
plotdevice = "/xserve"               // reset graph output to X
This can be done even shorter:
plot sin([-3600:3600]/10)
will plot a sine function without any annotation to the current plot device, overriding any previous plot. A very simple contour plot can also be done:
contour gauss(129,129,30,50,30), [1:9]*10
will do a contour plot of an elliptical gaussian with contour levels 10%, 20%, ..., 90%.