vector.hpp

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// vector.hpp
// 
// Copyright (c) 2009 - Michele De Stefano (micdestefano@users.sourceforge.net)
// 
// Distributed under the MIT License (See accompanying file LICENSE)

#ifndef MDS_UTILS_PYTHON_UBLAS_VECTOR_HPP_INCLUDED
#define MDS_UTILS_PYTHON_UBLAS_VECTOR_HPP_INCLUDED

#include <boost/numeric/ublas/vector.hpp>
#include <mds_utils/python/ublas/detail/common.hpp>
#include <mds_utils/ublas/traits.hpp>
#include <type_traits>


namespace mds_utils { namespace python {

    namespace ublas {
        
template<class ublas_vec_T>
inline typename std::enable_if<
    mds_utils::ublas::is_vector<ublas_vec_T>::value,ublas_vec_T>::type
        get(PyObject *po) {

    using namespace mds_utils::python::numpy;
    using namespace std;

    if (!PyArray_Check(po)) {
        throw std::invalid_argument("Cannot convert to "
            "boost::numeric::ublas::vector: not a numpy array.");
    }

    PyArrayObject   *m_po(reinterpret_cast<PyArrayObject*>(po));
    

    int                 ndim(PyArray_NDIM(m_po));
    
    if (ndim != 1 && ndim != 2) {
        throw std::invalid_argument("Cannot convert from an "
            "array with num. of dims. different from 2.");
    }
    
    npy_intp            *dims(PyArray_DIMS(m_po));
    
    if (!(ndim == 1 || std::min(dims[0],dims[1]) == 1)) {
        throw std::invalid_argument("Cannot convert from a non-vector");
    }
            
    ublas_vec_T
        vout((ndim == 1) ? *dims : *std::max_element(dims,dims+2));
    
    NDArrayIterator<
        typename ublas_vec_T::value_type,
        typename detail::ublas_to_npy_storage<
            boost::numeric::ublas::row_major_tag>::tag,NPY_ITER_READONLY>
                        it_beg(m_po),it_end(it_beg,true);

    copy(it_beg,it_end,vout.begin());

    return vout;
}


template<class ublas_vec_T>
inline typename std::enable_if<
    mds_utils::ublas::is_vector<ublas_vec_T>::value,
    PyObject*
            >::type to_python(const ublas_vec_T& v) {
    
    using namespace mds_utils::python::numpy;
    using namespace std;

    int
        nd(1),
        flags(0);
        
    npy_intp
        dims[] = {
            boost::numeric_cast<npy_intp>(v.size())
        };
    
    int dtype(numpy_dtype_traits<
        typename ublas_vec_T::value_type>::typenum);
    
    PyObject *pout(PyArray_New(&PyArray_Type,nd,dims,dtype,
        NULL,NULL,0,flags,NULL));
    
    if (pout == NULL) {
        throw std::runtime_error("Could not create output numpy array.");
    }
    
    PyArrayObject   *m_po(reinterpret_cast<PyArrayObject*>(pout));

    typedef typename ublas_vec_T::value_type            value_type;
    typedef typename detail::ublas_to_npy_storage<
            boost::numeric::ublas::row_major_tag>::tag  storage;

    NDArrayIterator<value_type,storage,NPY_ITER_WRITEONLY>  it_beg(m_po);

    copy(v.begin(),v.end(),it_beg);
    
    return pout;
}

    }

}}


#endif