Use of the IMSL C Libraries on science
--------------------------------------

To link the IMSL C libraries, first (from csh)

   source /usr/local/vni/ipt/bin/iptsetup.csh

This will set up the necessary environmental variables.

Your calling program should
  #include <imsl.h>

Then,

   CC -o <executable> $CFLAGS <source> $LINK_CNL

In $LINK_CNL there are apparently some libraries listed more than
once; therefore a linker statement like
  "The shared object /usr/lib/xxxx did not resolve any symbols.
        You may want to remove it from your link line."
may be returned.  Just ignore it.

Many IMSL C funtions have optional arguments.  For such functions, the
last argument is always a 0.

Online help is available.  The command is 
   iptdoc   
(which will be in the paths set when you source iptsetup.csh)
This program runs an X-window, so if you are running remotely, you
will need the DISPLAY variable to be set, and xhost privileges given
to science. 

Here are a couple of examples:

To generate 5 Gaussian random numbers:

#include <imsl.h>
#include <stdio.h>
void main()
{
    int   seed = 123457;
    int   n_random = 5;
    float *r;
    imsl_random_seed_set (seed);
    r = imsl_f_random_normal (n_random, 0);
    printf ("The random Gaussians are %8.4f%8.4f%8.4f%8.4f%8.4f\n",
            r[0], r[1], r[2], r[3], r[4]);
}

To solve the linear system

 3x_1 +2x_2 + x_3  & = & 11
  x_1 +4x_2 - x_3  & = & 3 
  x_1 - x_2 + 2x_3 & = & 7

#include <imsl.h>
#include <stdio.h>
void main()
{
    int   n = 3;
    float *x;
    float a[] = {3.0,  2.0,  1.0,
                 1.0,  4.0, -1.0,
                 1.0, -1.0,  2.0};
    float b[] = {11.0, 3.0, 7.0};
    x = imsl_f_lin_sol_gen (n, a, b, 0);
    printf ("The solution is %10.4f%10.4f%10.4f\n", x[0], x[1], x[2]);
}