[Insight-users] qury regarding vnl library of ITk

[Luis Ibanez]

Hi Chinmay,


1) The determinant of a 3x4 matrix is always zero.


2) vnl_det can only be called on "vnl_matrix_fixed" types.

Please do:

#include "vnl/vnl_det.h"
#include "vnl/vnl_matrix_fixed.h"
#include <iostream>

int main()
{
  vnl_matrix_fixed<double,3,3>  m;

  m(0,0) = 1;
  m(1,1) = 2;
  m(2,2) = 3;

  double det = vnl_det( m );

  std::cout << "det = " << det << std::endl;

  return 0;
}


     Thanks


          Luis


-------------------------------------
On Sat, Mar 5, 2011 at 8:02 PM, Chinmay Srivastav
<srivastavchinmay at gmail.com> wrote:
> Hi Luiz,
>
> I am a newbie in ITK and I am given a task to find out the determinant and
> rank of the matrix using ITK. I have written the following code:
>
> #include <itkMatrix.h>
> #include <vnl/vnl_matrix.h>
> #include <vnl/vnl_vector.h>
> #include <vnl/vnl_det.h>
>
> int main()
> {
>     vnl_matrix<double> P(3,4);
>     P.set_identity();
>     vcl_cerr << "The First matrix is ";
>     vcl_cerr <<P;
>      vnl_det(P);
>      return 0;
> }
>
> On building the code i get following error message:
>
> error: no matching function for call to 'vnl_det(vnl_matrix<double>&)'
>
> Unfortunately I am not able to debug this error. Kindly provide me help so
> that I can debug this error.
>
> Also provide me some link that provides good documentation about the vnl
> library. I have searched a lot but was unable to get good documentation
> regarding this especially for computing Determinant and Rank.
>
>
> Please help and oblige
>
> Thanks
> Regards
> Chinmaya Srivastava
>
>