done separately; the <code>f77</code> (or equivalent) command is used for linking to ensure that the required Fortran support libraries are loaded. It is possible to link using <code>cc</code> or <code>ld</code>, but you must then figure out which libraries your Fortran compiler needs (<code>man f77</code> might help).</li>

<li>The <code>-lcpgplot -lpgplot</code> options tell the linker to scan the PGPLOT libraries, and the <code>-L</code> option specifies a directory where the linker should look for them.