# include <cmath>
# include <complex>
# include <cstdlib>

using namespace std;

# include "eigs.hpp"

//****************************************************************************80

complex <double> *eigs ( int n, double *A )

//****************************************************************************80
//
//  Purpose:
//
//    eigs() computes the eigenvalues of a real matrix in general storage.
//
//  Discussion:
//
//    The computation is done by calling the lapack() function dgeev()
//
//  Licensing:
//
//    This code is distributed under the MIT license. 
//
//  Modified:
//
//    06 June 2024
//
//  Author:
//
//    John Burkardt
//
{
  int i;
  int info;
  char jobvl;
  char jobvr;
  complex <double> *lambda;
  int lda = n;
  int ldvl = 1;
  int ldvr = 1;
  int lwork;
  double *vl;
  double *vr;
  double *wi;
  double *work;
  double *wr;

  jobvl = 'N';
  jobvr = 'N';
  lda = n;
  wr = new double[n];
  wi = new double[n];
  vl = NULL;
  ldvl = 1;
  vr = NULL;
  ldvr = 1;
  work = new double[3*n];
  lwork = 3 * n;

  dgeev_ ( &jobvl, &jobvr, &n, A, &lda, wr, wi, vl, &ldvl, vr, &ldvr,
    work, &lwork, &info );

  lambda = new complex <double> [n];
  for ( i = 0; i < n; i++ )
  {
    lambda[i] = complex <double> ( wr[i], wi[i] );
  }

  delete [] wi;
  delete [] work;
  delete [] wr;

  return lambda;
}