Z-Axis Window

The Z-Axis window is show below in its default condition for a CP file. See the Zaxis window for image files only discussion for the cases of IMG, CMP or SGI raster files.

The Z-Axis window allows all of the settings associated with the raster data and the display of the Z-Axis colorbar to be controlled. These settings are discussed individually below. There are two other inputs that become visible if other settings are changed, these are the null value and Log Z inputs and they are shown below:

Settings

Maximum and Minimum Z values

These are the z data values that are mapped to the extremes of the colormap, and they are used as limits for the colorbar to the right of the body of the output plot.

Show Z scale

This settings determines whether the colorbar to the right of the plot is displayed.

Step for Z scale

This setting controls the number of color squares displayed in the colorbar.

Log Z

If the limits of the z scale are both greater than zero, it is posible to use logarithmic scaling on the z data when it is colormapped.

Null Color

This sets the background color of the plot and the color used when z values equal to the Z null value are encountered in the data file. If set to value the null data points are replaced by this color corresponding the the value entered into the value text box.

value

This value replaces any z value which have the z null data value.

Z Null

This is the data value that is replaced by either the color white or the color associated with the value discussed above.

Colormap

This list box allows selection of the colormap to be used for the CP file data. An NTSC in front of a colormap name means that the colormap only uses legal NTSC colors (restricted saturation, etc.). The word edges refers the the edges of the RGB color cube. These colormaps use only fully saturated colors.

Max/Min X and Y locations

For a CP file these text boxes are not editable and mearly display the extents of the CP file data from the selected file.

Z axis Label

This is the text that is written along the vertical colorbar to the right of the plot. It uses the same TeX like formating that is available in GFx axis labels and comments.

Z Scale Format Num Digits

This setting allows the number of digits in the Z axis colorbar labels to be selected.

Preserve Aspect (not shown)

See the raster file Z axis discussion.

The image below shows the Z-Axis window with some different choices selected and text box entries made. These settings were used to produce the output image shown on the first page of the PSALL manual.