General user environment

This module describes how to set up your work environment, shell variables, path names, and resource files to build Low Level Utility and High Level Utility applications, and run the NCAR Command Language.

Environment variables

Before you can use NCAR Graphics, you must make sure that you have set either NCARG_ROOT or the three environment variables NCARG_BIN, NCARG_LIB, and NCARG_INCLUDE, depending on how NCAR Graphics was installed on your system. In some cases, the installer may have set either NCARG_ROOT or NCARG_BIN, NCARG_LIB, and NCARG_INCLUDE globally so that you don't have to worry about it. To figure out if any of these variables have been set, execute:

A list of all the environment variables that have been set will be shown, along with their values.

If you don't have either NCARG_ROOT, or NCARG_BIN, NCARG_LIB, and NCARG_INCLUDE set, then please contact your system administrator.

Path names

You must have the NCAR Graphics binaries in your execution path. If you have the NCARG_ROOT environment variable set, then the location of these files is $NCARG_ROOT/bin, otherwise the location is $NCARG_BIN.

You must add one of these directories to your execution path in order to use the NCAR Graphics software. Contact your system administrator if you need help in adding a directory to your execution path.

Where to go from here

After you have set up the NCAR Graphics environment variables and path names described earlier, you are ready to use the NCAR Graphics software, build Low Level Utility and High Level Utility applications, and run the NCAR Command Language.

Using the LLUs

The NCAR Graphics Low Level Utilities currently contain the richest set of programming interfaces for developers to use to create NCAR Graphics applications. The LLUs consist of both a C and the traditional Fortran interface for creating graphics applications and visualizing scientific data. For more information about using the LLUs and creating an LLU application, see the Low Level Utilities module.

Using the HLUs

The High Level Utilities are a library of tools that provide a consistent programming interface to NCAR Graphics functionality. The HLU design makes it unnecessary for you to understand and control most of the low-level implementation details of the traditional NCAR Graphics software.

The HLUs exploit the benefits of resource files. Resource files are ASCII files that specify resources for controlling the characteristics of your NCAR Graphics plots. These files make it easy to control default plot attributes without having to recompile a program or reset the properties that you want to remain constant in all your NCAR Graphics applications. For more detailed information about setting up resource files in your user environment, see the HLU user environment module.

Using NCL

The NCAR Command Language is a higher level user interface that is built on top of the High Level Utilities. NCL is an interactive scripting language; it works in a fashion similar to a Unix shell scripting language. Before you can use the NCAR Command Language, you must set up your NCAR Graphics environment variables and path names as described earlier.

For more information about running NCL, see the NCL user environment module.

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$Revision: 1.7 $ $Date: 1998/06/15 22:07:47 $