/* nag_nag_opt_sparse_convex_qp_solve (e04nqc) Example Program.
 *
 * Copyright 2004 Numerical Algorithms Group.
 *
 * Mark 8, 2004.
 */

#include <stdio.h>
#include <string.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nage04.h>
#include <nagx04.h>

#ifdef __cplusplus
extern "C" {
#endif
static void NAG_CALL qphx(Integer ncolh, const double x[], double hx[],
                          Integer nstate, Nag_Comm *comm);
#ifdef __cplusplus
}
#endif

int main(int argc, char *argv[])
{
  FILE         *fpin, *fpout;
  char         *outfile;

  /* Scalars */
  double       obj, objadd, sinf;
  Integer      exit_status, i, icol, iobj, j, jcol, lenc, m, n, ncolh, ne,
               ninf;
  Integer      nname, ns;

  /* Arrays */
  char         nag_enum_arg[40];
  char         prob[9];
  char         **names;
  double       *acol = 0, *bl = 0, *bu = 0, *c = 0, *pi = 0, *rc = 0, *x = 0;
  Integer      *helast = 0, *hs = 0, *inda = 0, *loca = 0;

  /*Nag Types*/
  Nag_E04State state;
  NagError     fail;
  Nag_Start    start;
  Nag_Comm     comm;
  Nag_FileID   fileid;

  exit_status = 0;
  INIT_FAIL(fail);

  /* Check for command-line IO options */
  fpin = nag_example_file_io(argc, argv, "-data", NULL);
  fpout = nag_example_file_io(argc, argv, "-results", NULL);
  (void) nag_example_file_io(argc, argv, "-nag_write", &outfile);

  fprintf(fpout,
          "nag_opt_sparse_convex_qp_solve (e04nqc) Example Program Results\n");

  /* Skip heading in data file. */
  fscanf(fpin, "%*[^\n] ");

  /* Read ne, iobj, ncolh, start and nname from data file. */
  fscanf(fpin, "%ld%ld%*[^\n] ", &n, &m);
  fscanf(fpin, "%ld%ld%ld %s %ld%*[^\n] ",
         &ne, &iobj, &ncolh, nag_enum_arg, &nname);
  /* nag_enum_name_to_value(x04nac).
   * Converts NAG enum member name to value
   */
  start = (Nag_Start) nag_enum_name_to_value(nag_enum_arg);
  if (n >= 1 && m >= 1)
    {
      /* Allocate memory */
      if (!(names = NAG_ALLOC(n+m, char *)) ||
          !(acol = NAG_ALLOC(ne, double)) ||
          !(bl = NAG_ALLOC(m+n, double)) ||
          !(bu = NAG_ALLOC(m+n, double)) ||
          !(c = NAG_ALLOC(1, double)) ||
          !(pi = NAG_ALLOC(m, double)) ||
          !(rc = NAG_ALLOC(n+m, double)) ||
          !(x = NAG_ALLOC(n+m, double)) ||
          !(helast = NAG_ALLOC(n+m, Integer)) ||
          !(hs = NAG_ALLOC(n+m, Integer)) ||
          !(inda = NAG_ALLOC(ne, Integer)) ||
          !(loca = NAG_ALLOC(n+1, Integer)))
        {
          fprintf(fpout, "Allocation failure\n");
          exit_status = -1;
          goto END;
        }
    }
  else
    {
      fprintf(fpout, "%s", "Either m or n invalid\n");
      exit_status = 1;
      return exit_status;
    }

  /* Read names from data file. */
  for (i = 1; i <= nname; ++i)
    {
      names[i-1] = NAG_ALLOC(9, char);
      fscanf(fpin, " ' %8s '", names[i-1]);
    }
  fscanf(fpin, "%*[^\n] ");

  /* Read the matrix acol from data file. Set up LOCA. */
  jcol = 1;
  loca[jcol - 1] = 1;
  for (i = 1; i <= ne; ++i)
    {
      /* Element (inda[i-1], icol) is stored in acol[i-1]. */
      fscanf(fpin, "%lf%ld%ld%*[^\n] ", &acol[i - 1], &inda[i - 1],
             &icol);
      if (icol < jcol)
        {
          /* Elements not ordered by increasing column index. */
          fprintf(fpout, "%s%5ld%s%5ld%s%s\n", "Element in column",
                  icol, " found after element in column", jcol, ". Problem",
                  " abandoned.");
        }
      else if (icol == jcol + 1)
        {
          /* Index in ACOL of the start of the ICOL-th column equals I. */
          loca[icol - 1] = i;
          jcol = icol;
        }
      else if (icol > jcol + 1)
        {
          /* Index in acol of the start of the icol-th column equals i, */
          /* but columns jcol+1,jcol+2,...,icol-1 are empty. Set the */
          /* corresponding elements of loca to i. */
          for (j = jcol + 1; j <= icol - 1; ++j)
            {
              loca[j - 1] = i;
            }
          loca[icol - 1] = i;
          jcol = icol;
        }
    }
  loca[n] = ne + 1;

  if (n > icol)
    {
      /* Columns n,n-1,...,icol+1 are empty. Set the corresponding */
      /* elements of loca accordingly. */
      for (i = n; i >= icol + 1; --i)
        {
          loca[i - 1] = loca[i];
        }
    }

  /* Read bl, bu, hs and x from data file. */
  for (i = 1; i <= n + m; ++i)
    {
      fscanf(fpin, "%lf", &bl[i - 1]);
    }
  fscanf(fpin, "%*[^\n] ");

  for (i = 1; i <= n + m; ++i)
    {
      fscanf(fpin, "%lf", &bu[i - 1]);
    }
  fscanf(fpin, "%*[^\n] ");

  if (start == Nag_Cold)
    {
      for (i = 1; i <= n; ++i)
        {
          fscanf(fpin, "%ld", &hs[i - 1]);
        }
      fscanf(fpin, "%*[^\n] ");
    }
  else if (start == Nag_Warm)
    {
      for (i = 1; i <= n + m; ++i)
        {
          fscanf(fpin, "%ld", &hs[i - 1]);
        }
      fscanf(fpin, "%*[^\n] ");
    }
  for (i = 1; i <= n; ++i)
    {
      fscanf(fpin, "%lf", &x[i - 1]);
    }
  fscanf(fpin, "%*[^\n] ");

  /* nag_opt_sparse_convex_qp_init (e04npc).
   * Initialization function for
   * nag_opt_sparse_convex_qp_solve (e04nqc)
   */
  nag_opt_sparse_convex_qp_init(&state, &fail);
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Initialisation of "
              "nag_opt_sparse_convex_qp_solve (e04nqc) failed.\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }
  /* By default nag_opt_sparse_convex_qp_solve (e04nqc) does not print
   * monitoring information. Call nag_open_file (x04acc) to set the print file
   * fileid */
  /* nag_open_file (x04acc).
   * Open unit number for reading, writing or appending, and
   * associate unit with named file
   */
  if (outfile) fclose(fpout);
  nag_open_file(outfile, 2, &fileid, &fail);
  if (fail.code != NE_NOERROR)
    {
      exit_status = 2;
      goto END;
    }

  /* nag_opt_sparse_convex_qp_option_set_integer (e04ntc).
   * Set a single option for nag_opt_sparse_convex_qp_solve (e04nqc)
   * from an integer argument
   */
  nag_opt_sparse_convex_qp_option_set_integer("Print file", fileid, &state,
                                              &fail);
  if (fail.code != NE_NOERROR)
    {
      nag_close_file(fileid, &fail);
      exit_status = 1;
      goto END;
    }

  /* We have no explicit objective vector so set lenc = 0; the
   * objective vector is stored in row iobj of acol.
   */
  lenc = 0;
  objadd = 0.;
  strcpy(prob, "");

  /* Do not allow any elastic variables (i.e. they cannot be */
  /* infeasible). If we'd set optional argument "Elastic mode" to 0, */
  /* we wouldn't need to set the individual elements of array helast. */
  for (i = 1; i <= n + m; ++i)
    {
      helast[i - 1] = 0;
    }

  /* Solve the QP problem. */
  /* nag_opt_sparse_convex_qp_solve (e04nqc).
   * LP or QP problem (suitable for sparse problems)
   */
  nag_opt_sparse_convex_qp_solve(start, qphx, m, n, ne, nname, lenc, ncolh,
                                 iobj, objadd, prob, acol, inda, loca, bl, bu,
                                 c, names, helast, hs, x, pi, rc, &ns, &ninf,
                                 &sinf, &obj, &state, &comm, &fail);

  if (outfile && !(fpout = fopen(outfile, "a")))
    {
      exit_status = 2;
      goto END;
    }
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "nag_opt_sparse_convex_qp_solve (e04nqc) failed.\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }
  nag_close_file(fileid, &fail);
  if (fail.code != NE_NOERROR)
    {
      exit_status = 2;
      goto END;
    }

  fprintf(fpout, "Final objective value = %12.3e\n", obj);
  fprintf(fpout, "Optimal X = ");

  for (i = 1; i <= n; ++i)
    {
      fprintf(fpout, "%9.2f%s", x[i - 1], i%7 == 0 || i == n?"\n":" ");
    }

 END:
  if (fpin != stdin) fclose(fpin);
  if (fpout != stdout) fclose(fpout);
  for (i = 0; i < n+m; i++)
    {
      if (names[i]) NAG_FREE(names[i]);
    }
  if (names) NAG_FREE(names);
  if (acol) NAG_FREE(acol);
  if (bl) NAG_FREE(bl);
  if (bu) NAG_FREE(bu);
  if (c) NAG_FREE(c);
  if (pi) NAG_FREE(pi);
  if (rc) NAG_FREE(rc);
  if (x) NAG_FREE(x);
  if (helast) NAG_FREE(helast);
  if (hs) NAG_FREE(hs);
  if (inda) NAG_FREE(inda);
  if (loca) NAG_FREE(loca);
  return exit_status;
}

static void NAG_CALL qphx(Integer ncolh, const double x[], double hx[],
                          Integer nstate, Nag_Comm *comm)
{
  /* Routine to compute H*x. (In this version of qphx, the Hessian
   * matrix H is not referenced explicitly.)
   */

  /* Parameter adjustments */
#define HX(I) hx[(I) -1]
#define X(I)  x[(I) -1]

  /* Function Body */
  HX(1) = X(1) * 2;
  HX(2) = X(2) * 2;
  HX(3) = (X(3) + X(4)) * 2;
  HX(4) = HX(3);
  HX(5) = X(5) * 2;
  HX(6) = (X(6) + X(7)) * 2;
  HX(7) = HX(6);
  return;
} /* qphx */