n defining <code>LD_LIBRARY_PATH</code> to include directories that other programs may need to search, as well as the PGPLOT directory. Not all UNIX systems use <code>LD_LIBRARY_PATH</code>: see the documentation for your system. On some systems, you can use the <code>-R</code> option (or an equivalent one) of <code>ld</code> to specify a search directory for the library when you link the program; then the search directory is attached to the executable program and doesn't need to be specified by <code>LD_LI