/* nag_sum_sqs_update (g02btc) Example Program.
 *
 * Copyright 2002 Numerical Algorithms Group.
 *
 * Mark 7, 2002.
 */

#include <stdio.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nag_string.h>
#include <nagf06.h>
#include <nagg02.h>
#include <nagx04.h>

int main(void)
{
  /* Scalars */
  double alpha, sw, wt;
  Integer exit_status, i, j, m, mm, n, nprint, incx;
  NagError fail;
  Nag_SumSquare mean_enum;

  /* Arrays */
  char mean[2];
  double *c=0, *v=0, *x=0, *xbar=0;

  INIT_FAIL(fail);
  exit_status = 0;
  Vprintf("g02btc Example Program Results\n");

  /* Skip heading in data file */
  Vscanf("%*[^\n] ");

  incx = 1;
  while (scanf("' %1s '%ld%ld%ld%*[^\n]", mean, &m, &n, &nprint) != EOF)
    {
      /* Allocate memory */
      if ( !(c = NAG_ALLOC((m*m+m)/2, double)) ||
           !(v = NAG_ALLOC((m*m+m)/2, double)) ||
           !(x = NAG_ALLOC(m*incx, double)) ||
           !(xbar = NAG_ALLOC(m, double)) )
        {
          Vprintf("Allocation failure\n");
          exit_status = -1;
          goto END;
        }

      sw = 0.0;
      for (i = 1; i <= n; ++i)
        {
          Vscanf("%lf", &wt);
          for (j = 1; j <= m; ++j)
            Vscanf("%lf", &x[j - 1]);
          Vscanf("%*[^\n] ");

          if (mean[0] == 'M')
            mean_enum = Nag_AboutMean;
          else if (mean[0] == 'Z')
            mean_enum = Nag_AboutZero;
          else
            {
              Vprintf("Incorrect value for mean\n");
              exit_status = -1;
              goto END;
            }

          /* Calculate the sums of squares and cross-products matrix */
          g02btc(mean_enum, m, wt, x, incx, &sw, xbar, c, &fail);

          if (fail.code != NE_NOERROR)
            {
              Vprintf("Error from g02btc.\n%s\n", fail.message);
              exit_status = 1;
              goto END;
            }

          if (i % nprint == 0 || i == n)
            {
              Vprintf("\n");
              Vprintf("---------------------------------------------\n");
              Vprintf("Observation: %4ld      Weight = %13.4f\n", i,  wt);
              Vprintf("\n");
              Vprintf("---------------------------------------------\n");
              Vprintf("\n");

              Vprintf("Means\n");
              for (j = 1; j <= m; ++j)
                Vprintf("%14.4f%s", xbar[j - 1], j%4 == 0 || j == m ? "\n":" ");
              Vprintf("\n");

              /* Print the sums of squares and cross products matrix */
              x04ccc(Nag_ColMajor, Nag_Upper, Nag_NonUnitDiag, m, c,
                     "Sums of squares and cross-products", 0, &fail);
              if (fail.code != NE_NOERROR)
                {
                  Vprintf("Error from x04ccc.\n%s\n", fail.message);
                  exit_status = 1;
                  goto END;
                }
              if (sw > 1.0)
                {
                  /* Calculate the variance matrix */
                  alpha = 1.0 / (sw - 1.0);
                  mm = m * (m + 1) / 2;
                  f06fdc(mm, alpha, c, 1, v, 1);

                  /* Print the variance matrix */
                  Vprintf("\n");
                  x04ccc(Nag_ColMajor, Nag_Upper, Nag_NonUnitDiag, m, v,
                         "Variance matrix", 0, &fail);
                  if (fail.code != NE_NOERROR)
                    {
                      Vprintf("Error from x04ccc.\n%s\n", fail.message);
                      exit_status = 1;
                      goto END;
                    }
                }
            }
        }

      if (c) NAG_FREE(c);
      if (v) NAG_FREE(v);
      if (x) NAG_FREE(x);
      if (xbar) NAG_FREE(xbar);
    }

 END:
  if (c) NAG_FREE(c);
  if (v) NAG_FREE(v);
  if (x) NAG_FREE(x);
  if (xbar) NAG_FREE(xbar);

  return exit_status;
}