Program Listing for File tensors.h

↰ Return to documentation for file (source/utilities/tensors.h)

/*
 * tensors.h Utilities to help with Eigen::Tensors
 *
 * Author:              Tom Clark  (thclark @ github)
 *
 * Copyright (c) 2019 Octue Ltd. All Rights Reserved.
 *
 */

#ifndef ES_FLOW_TENSORS_H
#define ES_FLOW_TENSORS_H

#include <unsupported/Eigen/CXX11/Tensor>
#include <iostream>
#include <string>


namespace utilities {


template<typename T>
using  MatrixType = Eigen::Matrix<T,Eigen::Dynamic, Eigen::Dynamic>;


template<typename T>
using  ArrayType = Eigen::Array<T,Eigen::Dynamic, Eigen::Dynamic>;


template<typename Scalar,int rank, typename sizeType>
auto tensor_to_matrix(const Eigen::Tensor<Scalar,rank> &tensor,const sizeType rows,const sizeType cols)
{
    return Eigen::Map<const MatrixType<Scalar>> (tensor.data(), rows,cols);
}


template<typename Scalar, typename... Dims>
auto matrix_to_tensor(const MatrixType<Scalar> &matrix, Dims... dims)
{
    constexpr int rank = sizeof... (Dims);
    return Eigen::TensorMap<Eigen::Tensor<const Scalar, rank>>(matrix.data(), {dims...});
}


template<typename Scalar,int rank, typename sizeType>
auto tensor_to_array(const Eigen::Tensor<Scalar,rank> &tensor,const sizeType rows,const sizeType cols)
{
    return Eigen::Map<const ArrayType<Scalar>> (tensor.data(), rows,cols);
}


template<typename Scalar, typename... Dims>
auto array_to_tensor(const ArrayType<Scalar> &matrix, Dims... dims)
{
    constexpr int rank = sizeof... (Dims);
    return Eigen::TensorMap<Eigen::Tensor<const Scalar, rank>>(matrix.data(), {dims...});
}


template<typename T>
std::string tensor_dims(T &tensor) {
    std::stringstream dims;
    for (auto i = tensor.dimensions().begin(); i != tensor.dimensions().end(); ++i) {
        dims << *i << " x ";
    }
    std::string dim_str = dims.str();
    dim_str.pop_back();
    dim_str.pop_back();
    dim_str.pop_back();
    return dim_str;
}

} /* namespace utilities */

#endif //ES_FLOW_TENSORS_H