/* F08KP_P0W_F C++ Header Example Program.
 *
 * Copyright 2021 Numerical Algorithms Group.
 * Mark 27.2, 2021.
 */

#include <iostream>
#include <nag.h>
#include <nagad.h>
#include <nagx04.h>
#include <stdio.h>
#include <string>
using namespace std;

int main(void)
{
  int      exit_status = 0;
  void *   ad_handle   = 0;
  Integer  ifail       = 0;
  NagError fail;
  INIT_FAIL(fail);

  cout << "F08KP_P0W_F C++ Header Example Program Results\n\n";
  // Skip heading in data file
  string mystr;
  getline(cin, mystr);

  // Read matrix dimensions
  Integer m, n;
  cin >> m;
  cin >> n;

  // Allocate arrays containing A and its factorized form, B
  // and the solution X.
  Integer  lda = m, ldu = m, ldvt = n, lwork;
  Complex *a = 0, *u = 0, *vt = 0, *work = 0, dummy[1];
  double * s = 0, *rwork = 0;
  Charlen  lena = 1;
  a             = new Complex[m * n];
  s             = new double[m];
  rwork         = new double[5 * n];
  u             = new Complex[m * m];
  vt            = new Complex[n * n];

  // Read the matrix A, register and copy
  double dd, di;
  for (int i = 0; i < m; i++)
    {
      for (int j = 0; j < n; j++)
        {
          cin >> dd >> di;
          Integer k = i + j * m;
          a[k].re   = dd;
          a[k].im   = di;
        }
    }

  // Use routine workspace query to get optimal workspace.
  ifail = 0;
  lwork = -1;
  nag::ad::f08kp(ad_handle, "A", "A", m, n, a, lda, s, u, ldu, vt, ldvt, dummy,
                 lwork, rwork, ifail);

  lwork = (Integer)dummy[0].re + 1;
  work  = new Complex[lwork];

  //  Compute the singular values and left and right singular vectors
  //  of A (A = U*S*(V**T), m < n)
  nag::ad::f08kp(ad_handle, "A", "A", m, n, a, lda, s, u, ldu, vt, ldvt, work,
                 lwork, rwork, ifail);

  // Print primal solution
  cout.precision(4);
  cout.width(12);
  cout << " ";
  cout << " Singular values:\n";
  for (int i = 0; i < n; i++)
    {
      cout.width(11);
      cout << s[i];
    }

  cout << "\n\n";
  x04dac(Nag_ColMajor, Nag_GeneralMatrix, Nag_NonUnitDiag, m, m, u, m,
         "Left singular vectors by column", 0, &fail);
  cout << "\n";
  x04dac(Nag_ColMajor, Nag_GeneralMatrix, Nag_NonUnitDiag, n, n, vt, n,
         "Right singular vectors by row", 0, &fail);

  delete[] a;
  delete[] s;
  delete[] u;
  delete[] vt;
  delete[] work;
  delete[] rwork;

  return exit_status;
}