>"

You can see what options are available to you by clicking on
the **Graph** button in Figure 3.

Figure 10 Graphing Options

Keep in mind that some of these options are available only for
the cartesian graph for the data set ex2_1.sds.

A *contour plot* contains contour lines between areas
of differing contour levels. A *contour level* is a range of data
values that you want to distinguish from other ranges of values.
For the example program given in the introduction, you will want
the graphing options box to have the **Plot Cartesian** option
showing. Clicking on the **Contour** button calls up the
contour specifications window.
Here you may specify the number and spacing of contour levels as
well as the range of data values to be distinguished. Choosing
the Number of Levels to be *57*, the Min Value to be
*-350*, and the Max Value to be *350*, you should
something similar to Figure 11.
Figure 11 Contour Mapping

A shaded data plot represents data values as eight different intensities
of shading.
This option will work
for either the cartesian graph or the polar graph.
The new window, Figure 12,
is a black and white representation of your color
raster maps.
Figure 12 Shading of Cartesian and Polar Graphs

This will work for the cartesian graphs or the polar graphs,
but not at the same time. First,
click on the **Display Cartesian** option of
Figure 3. Now that you have
the cartesian window open, with the desired palette, click
on the *Select Point* option until it changes to
*Select Area*. Use the left button of the mouse to
`rubberband' the desired area of the graph you wish to
see represented in the histogram (this is done by clicking
on the left mouse button and holding it while you move it
in a diagonal direction, then letting the button go
once you have the boxed in the area you want).
You can also view the histogram without
rubberband boxing any area at all. X Image will assume you mean
to have the whole graph represented. This is what will happen
if you choose the *Plot Polar* option. Since there is
no way to specify a certain region of the polar graph, the
histogram represents the entire graph.
Figure 13 shows
an example of a histogram, along with the corresponding cartesian
graph.
Figure 13 Histogram and Corresponding Cartesian Graph

The *profile* option plots the frequency of data values
as a height. To create the profile, you must first have the
cartesian graph window open. In the upper left hand corner
of the cartesian graph window, click on the toggle until it
gives you the *Select Line* option. Then move the mouse
into the graph, and click with the left mouse button where
you wish the line to begin, and hold the button down while you
move the mouse to the end of your line. One that is done, you
should be able to see the line in the cartesian graph. Now
go back to the graphing options window, and click on **Profile**
for a window similar to Figure 14.
Figure 14 Profile Graph