topic Re: Using zgeev and complex matrices in Intel® oneAPI Math Kernel Library

Using zgeev and complex matrices

gatts — Wed, 29 Oct 2008 04:34:34 GMT

Well after a "rough landing" with dsyevr, I moved to zgeev, to get the eigenvalues and eigenvectors of a matrix, for this I use the following commands...

[cpp]
#include 

//Input values for zgeev
  char jobvl= 'V'; 
  char jobvr= 'N';

  int n = 500;
  int n2 = 2*n;

  int lda = n;

  complex *H = new complex[lda*n];

  int ldvl = n;
  int ldvr = n;

  int lwork = 2*n-1 ;

  complex *work = new complex[lwork];
 
  double *rwork = new double[n2];

  //Output values of zgeev

 double *wr = new double;
 double *wi = new double;

 
 complex *w = new complex;

 complex *vl = new complex[ldvl*n];
 complex *vr = new complex[ldvr*n];

 zgeev(&jobvl, &jobvr, &n, H, &lda, w, vl, &ldvl, vr, &ldvr, work, &lwork, rwork, &info);
[/cpp]

But it was strange beacuse send me this error, when compiling with the instruction "icc file.cpp -lmkl_em64t -openmp "

error: argument of type "std::complex *" is incompatible with parameter of type "MKL_Complex16 *"
zgeev(&jobvl, &jobvr, &n, H, &lda, w, vl, &ldvl, vr, &ldvr, work, &lwork, rwork, &info);

For H, work, vl,vr, in summary all the arrays of the system, wich I was expecting to work smoothly... I don't know what's happening, "googled" the error but didn't find anything useful... so i wish to ask how to declare the matrix of the system...

thanks in advances...

Re: Using zgeev and complex matrices

TimP — Wed, 29 Oct 2008 12:48:04 GMT

According to my understanding, C99 _Complex is supported by MKL, but not C++ std::complex. I couldn't see how you were using the MKL headers or how you invoked icpc.

Re: Using zgeev and complex matrices

gatts — Thu, 30 Oct 2008 01:36:55 GMT

Quoting - tim18

According to my understanding, C99 _Complex is supported by MKL, but not C++ std::complex. I couldn't see how you were using the MKL headers or how you invoked icpc.

Sure, I didn't post that part of the program but is included... in the include section: #include

Re: Using zgeev and complex matrices

Andrey_Bespalov — Thu, 30 Oct 2008 09:57:35 GMT

Some parameters of zgeev should be MKL_Complex* type. See below citations from the header files.

void zgeev( char *jobvl, char *jobvr, MKL_INT *n, MKL_Complex16 *a, MKL_INT *lda, MKL_Complex16 *w, MKL_Complex16 *vl, MKL_INT *ldvl, MKL_Complex16 *vr, MKL_INT *ldvr, MKL_Complex16 *work, MKL_INT *lwork, double *rwork, MKL_INT *info );

/* Complex type (double precision). */
#ifndef MKL_Complex16
typedef
struct _MKL_Complex16 {
double real;
double imag;
} MKL_Complex16;
#endif