Basic example 5

How to manipulate a colormap

This is an introductory example that shows how to manipulate colormaps using HLU C, HLU FORTRAN library calls, and NCL. The example demonstrates how to change color tables, how to alter a colormap entry, and how to create a completely new colormap. The names of the example codes that create this plot are basic05n.ncl, basic05c.c, and basic05f.f.

Discussion

This module demonstrates how to assign one of the predefined colormaps to a workstation object and then draw a labelbar that displays the current colormap. This example displays each of the NCAR Graphics pre-defined colormaps in a single frame. The example also shows how to read a colormap array, alter entries in that array, and then reassign the colormap. Finally, this example demonstrates how to create a completely new colormap array and then apply it to a workstation object.

A detailed discussion about how to create the plots appears in the comments of the source code for the example.

Creating the plot using HLU C library calls

The HLU C program that generates this plot is called basic05c.c.

Creating the plot using HLU FORTRAN library calls

The HLU FORTRAN program that generates this plot is called basic05f.f.

Creating the plot using NCL

The HLU NCL program that generates this plot is called basic05n.ncl.

The data

No external data is used with this example.

How to run this example

The examples are installed in the following locations:

You can copy this example and run it by typing "ng4ex basic05n", "ng4ex basic05c", or "ng4ex basic05f". A copy of the source file will be placed in your current working directory. The source code will be compiled (if appropriate) and automatically run for you.

Quick Start Guide Control Panel

NG4.1 Home, Index, Examples, Glossary, Feedback, QSG Contents, QSG WhereAmI?

$Revision: 1.10 $ $Date: 1999/03/23 18:28:10 $