NAG Library Manual, Mark 30.2
Interfaces:  FL   CL   CPP   AD 

NAG CL Interface Introduction
Example description
/* nag_mv_discrim (g03dac) Example Program.
 *
 * Copyright 2024 Numerical Algorithms Group.
 *
 * Mark 30.2, 2024.
 *
 */

#include <nag.h>
#include <stdio.h>

#define GMEAN(I, J) gmean[(I)*tdgmean + J]
#define X(I, J) x[(I)*tdx + J]
int main(void) {
  Integer exit_status = 0, i, *ing = 0, *isx = 0, j, m, n, ng, *nig = 0, nvar,
          tdgmean;
  Integer tdx;
  NagError fail;
  char weight[2];
  double *det = 0, df, *gc = 0, *gmean = 0, sig, stat, *wt = 0, *wtptr = 0;
  double *x = 0;

  INIT_FAIL(fail);

  printf("nag_mv_discrim (g03dac) Example Program Results\n\n");

  /* Skip headings in data file */
  scanf("%*[^\n]");
  scanf("%" NAG_IFMT "", &n);
  scanf("%" NAG_IFMT "", &m);
  scanf("%" NAG_IFMT "", &nvar);
  scanf("%" NAG_IFMT "", &ng);
  scanf("%1s", weight);
  if (n >= 1 && nvar >= 1 && m >= nvar && ng >= 2) {
    if (!(det = NAG_ALLOC(ng, double)) ||
        !(gc = NAG_ALLOC((ng + 1) * nvar * (nvar + 1) / 2, double)) ||
        !(gmean = NAG_ALLOC(ng * nvar, double)) ||
        !(wt = NAG_ALLOC(n, double)) || !(x = NAG_ALLOC(n * m, double)) ||
        !(ing = NAG_ALLOC(n, Integer)) || !(isx = NAG_ALLOC(m, Integer)) ||
        !(nig = NAG_ALLOC(ng, Integer))) {
      printf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }
    tdgmean = nvar;
    tdx = m;
  } else {
    printf("Invalid n or nvar or m or ng.\n");
    exit_status = 1;
    return exit_status;
  }
  if (*weight == 'W') {
    for (i = 0; i < n; ++i) {
      for (j = 0; j < m; ++j)
        scanf("%lf", &X(i, j));
      scanf("%" NAG_IFMT "", &ing[i]);
      scanf("%lf", &wt[i]);
    }
    wtptr = wt;
  } else {
    for (i = 0; i < n; ++i) {
      for (j = 0; j < m; ++j)
        scanf("%lf", &X(i, j));
      scanf("%" NAG_IFMT "", &ing[i]);
    }
  }
  for (j = 0; j < m; ++j)
    scanf("%" NAG_IFMT "", &isx[j]);

  /* nag_mv_discrim (g03dac).
   * Test for equality of within-group covariance matrices
   */
  nag_mv_discrim(n, m, x, tdx, isx, nvar, ing, ng, wtptr, nig, gmean, tdgmean,
                 det, gc, &stat, &df, &sig, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_mv_discrim (g03dac).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }

  printf("\nGroup means\n\n");
  for (i = 0; i < ng; ++i) {
    for (j = 0; j < nvar; ++j)
      printf("%10.4f", GMEAN(i, j));
    printf("\n");
  }
  printf("\nLOG of determinants\n\n");
  for (j = 0; j < ng; ++j)
    printf("%10.4f", det[j]);
  printf("\n\n%s%7.4f\n", "stat = ", stat);
  printf("%s%7.4f\n", "  df = ", df);
  printf("%s%7.4f\n", " sig = ", sig);
END:
  NAG_FREE(det);
  NAG_FREE(gc);
  NAG_FREE(gmean);
  NAG_FREE(wt);
  NAG_FREE(x);
  NAG_FREE(ing);
  NAG_FREE(isx);
  NAG_FREE(nig);
  return exit_status;
}