/* F08KB_P0W_F C++ Header Example Program.
 *
 * Copyright 2019 Numerical Algorithms Group.
 * Mark 27, 2019.
 */

#include <nag.h>
#include <nagx04.h>
#include <nagad.h>
#include <stdio.h>
#include <iostream>
#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 << "F08KB_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;
  double  *a=0, *s=0, *u=0, *vt=0, *work=0;
  Charlen lena = 1;
  a     = new double [m*n];
  s     = new double [m];
  u     = new double [m*m];
  vt    = new double [n*n];

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

  // Use routine workspace query to get optimal workspace.
  double dummy[1];
  ifail = 0;
  lwork = -1;
  f08kb_p0w_f_(ad_handle,"A","A",m,n,a,lda,s,u,ldu,vt,ldvt,dummy,lwork,ifail,
               lena,lena);

  lwork = (Integer) dummy[0] + 1;
  work = new double [lwork];

  //  Compute the singular values and left and right singular vectors
  //  of A (A = U*S*(V**T), m < n)
  f08kb_p0w_f_(ad_handle,"A","A",m,n,a,lda,s,u,ldu,vt,ldvt,work,lwork,ifail,
               lena,lena);

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

  cout << "\n\n";
  x04cac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,m,m,u,ldu,
         "Left singular vectors by column",0,&fail);
  cout << "\n";
  x04cac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,m,n,vt,ldvt,
         "Right singular vectors by row",0,&fail);

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

  return exit_status;
}