[ITK-users] vnl matrix to numpy array gives random numbers

[Nick Cullen]

Oh and to be clear, it gives me random numbers <i>after</i> I hit the numpy view and such (i.e.g ndarrview  = numpy.asarray(memview).view(dtype = numpydatatype).reshape(shape).view(numpy.ndarray)) 

    On Monday, August 7, 2017 10:27 PM, Nick Cullen <nickmarch31 at yahoo.com> wrote:
 

 Hi Friends !!
I'm trying to use itkPyVnl directly in ITK, but I must be getting something wrong with pointers... The following just gives me random numbers:
```    typedef typename ImageType::DirectionType ImageDirectionType;        ImageDirectionType * direction = const_cast<ImageDirectionType *>( &image->GetDirection() );
    typedef typename ImageDirectionType::InternalMatrixType DirectionInternalMatrixType;    DirectionInternalMatrixType * fixed_matrix = const_cast<DirectionInternalMatrixType *>( &direction->GetVnlMatrix() );
    const vnl_matrix<double> vnlmat1 = fixed_matrix->as_matrix();    vnl_matrix<double> * vnlmat2 = const_cast<vnl_matrix<double> *>( &vnlmat1 );
    typedef itk::PyVnl<double> PyVnlType;    PyObject * mymatrix = PyVnlType::_GetArrayViewFromVnlMatrix( vnlmat2 );```
I've tried a million different things and have problems either 1) due to the constness of ->as_matrix() and others or 2) due to "taking the address of a temporary object" with ->as_matrix() ... -__-

I know that this works:
```    vnl_matrix<double> * vnlmat = new vnl_matrix<double>;    vnlmat->set_size(2,3);    vnlmat->fill(0);    vnlmat->put(1,2,1.3);    vnlmat->put(1,0,2);    std::cout << vnlmat << std::endl;
    typedef itk::PyVnl<double> PyVnlType;    PyObject * mymatrix = PyVnlType::_GetArrayViewFromVnlMatrix( vnlmat );```
Any help above is MUCH appreciated !!!!

   
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