NAG Library Manual, Mark 30.1
Interfaces:  FL   CL   CPP   AD 

NAG CL Interface Introduction
Example description
/* nag_mv_discrim_group (g03dcc) Example Program.
 *
 * Copyright 2024 Numerical Algorithms Group.
 *
 * Mark 30.1, 2024.
 *
 */

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

#define ATI(I, J) ati[(I)*tdati + J]
#define P(I, J) p[(I)*tdp + J]
#define X(I, J) x[(I)*tdx + J]

int main(void) {
  Integer exit_status = 0, i, *iag = 0, *ing = 0, *isx = 0, j, m, n, ng,
          *nig = 0, nobs;
  Integer nvar, tdati, tdgmean, tdp, tdx;
  double *ati = 0, *det = 0, df, *gc = 0, *gmean = 0, *p = 0;
  double *prior = 0, sig, stat, *wt = 0, *wtptr = 0, *x = 0;
  char nag_enum_arg[40];
  Nag_Boolean atiq = Nag_TRUE, weight;
  Nag_DiscrimMethod type;
  Nag_GroupCovars equal;
  NagError fail;

  INIT_FAIL(fail);

  printf("nag_mv_discrim_group (g03dcc) 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("%39s", nag_enum_arg);
  /* nag_enum_name_to_value (x04nac).
   * Converts NAG enum member name to value
   */
  weight = (Nag_Boolean)nag_enum_name_to_value(nag_enum_arg);

  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)) ||
        !(prior = NAG_ALLOC(ng, 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 ng.\n");
    exit_status = 1;
    return exit_status;
  }
  if (weight) {
    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;
  }
  scanf("%" NAG_IFMT "", &nobs);
  scanf("%39s", nag_enum_arg);
  equal = (Nag_GroupCovars)nag_enum_name_to_value(nag_enum_arg);
  scanf("%39s", nag_enum_arg);
  type = (Nag_DiscrimMethod)nag_enum_name_to_value(nag_enum_arg);
  if (nobs >= 1) {
    if (!(ati = NAG_ALLOC((nobs) * (ng), double)) ||
        !(p = NAG_ALLOC((nobs) * (ng), double)) ||
        !(iag = NAG_ALLOC(nobs, Integer))) {
      printf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }
    tdati = ng;
    tdp = ng;
    for (i = 0; i < nobs; ++i) {
      for (j = 0; j < m; ++j) {
        scanf("%lf", &X(i, j));
      }
    }

    /* nag_mv_discrim_group (g03dcc).
     * Allocates observations to groups, following
     * nag_mv_discrim (g03dac)
     */
    nag_mv_discrim_group(type, equal, Nag_EqualPrior, nvar, ng, nig, gmean,
                         tdgmean, gc, det, nobs, m, isx, x, tdx, prior, p, tdp,
                         iag, atiq, ati, &fail);
    if (fail.code != NE_NOERROR) {
      printf("Error from nag_mv_discrim_group (g03dcc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

    printf("\n");
    printf("    Obs       Posterior        Allocated ");
    printf("      Atypicality ");
    printf("\n");
    printf("              probabilities    to group      index ");
    printf("\n");
    printf("\n");
    for (i = 0; i < nobs; ++i) {
      printf(" %6" NAG_IFMT "     ", i + 1);
      for (j = 0; j < ng; ++j) {
        printf("%6.3f", P(i, j));
      }
      printf("  %6" NAG_IFMT "    ", iag[i]);
      for (j = 0; j < ng; ++j) {
        printf("%6.3f", ATI(i, j));
      }
      printf("\n");
    }
  }

END:
  NAG_FREE(ati);
  NAG_FREE(det);
  NAG_FREE(gc);
  NAG_FREE(gmean);
  NAG_FREE(p);
  NAG_FREE(prior);
  NAG_FREE(wt);
  NAG_FREE(x);
  NAG_FREE(iag);
  NAG_FREE(ing);
  NAG_FREE(isx);
  NAG_FREE(nig);
  return exit_status;
}