text: // This file is part of Eigen, a lightweight C++ template library
  // for linear algebra.
  //
  // Copyright (C) 2014 Benoit Steiner <benoit.steiner.goog@gmail.com>
  //
  // This Source Code Form is subject to the terms of the Mozilla
  // Public License v. 2.0. If a copy of the MPL was not distributed
  // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
  
  #include "main.h"
  
  #include <Eigen/CXX11/Tensor>
  
  using Eigen::Tensor;
  
  template<int DataLayout>
  static void test_simple_patch()
  {
    Tensor<float, 4, DataLayout> tensor(2,3,5,7);
    tensor.setRandom();
    array<ptrdiff_t, 4> patch_dims;
  
    patch_dims[0] = 1;
    patch_dims[1] = 1;
    patch_dims[2] = 1;
    patch_dims[3] = 1;
  
    Tensor<float, 5, DataLayout> no_patch;
    no_patch = tensor.extract_patches(patch_dims);
  
    if (DataLayout == ColMajor) {
      VERIFY_IS_EQUAL(no_patch.dimension(0), 1);
      VERIFY_IS_EQUAL(no_patch.dimension(1), 1);
      VERIFY_IS_EQUAL(no_patch.dimension(2), 1);
      VERIFY_IS_EQUAL(no_patch.dimension(3), 1);
      VERIFY_IS_EQUAL(no_patch.dimension(4), tensor.size());
    } else {
      VERIFY_IS_EQUAL(no_patch.dimension(0), tensor.size());
      VERIFY_IS_EQUAL(no_patch.dimension(1), 1);
      VERIFY_IS_EQUAL(no_patch.dimension(2), 1);
      VERIFY_IS_EQUAL(no_patch.dimension(3), 1);
      VERIFY_IS_EQUAL(no_patch.dimension(4), 1);
    }
  
    for (int i = 0; i < tensor.size(); ++i) {
      VERIFY_IS_EQUAL(tensor.data()[i], no_patch.data()[i]);
    }
  
    patch_dims[0] = 2;
    patch_dims[1] = 3;
    patch_dims[2] = 5;
    patch_dims[3] = 7;
    Tensor<float, 5, DataLayout> single_patch;
    single_patch = tensor.extract_patches(patch_dims);
  
    if (DataLayout == ColMajor) {
      VERIFY_IS_EQUAL(single_patch.dimension(0), 2);
      VERIFY_IS_EQUAL(single_patch.dimension(1), 3);
      VERIFY_IS_EQUAL(single_patch.dimension(2), 5);
      VERIFY_IS_EQUAL(single_patch.dimension(3), 7);
      VERIFY_IS_EQUAL(single_patch.dimension(4), 1);
    } else {
      VERIFY_IS_EQUAL(single_patch.dimension(0), 1);
      VERIFY_IS_EQUAL(single_patch.dimension(1), 2);
      VERIFY_IS_EQUAL(single_patch.dimension(2), 3);
      VERIFY_IS_EQUAL(single_patch.dimension(3), 5);
      VERIFY_IS_EQUAL(single_patch.dimension(4), 7);
    }
  
    for (int i = 0; i < tensor.size(); ++i) {
      VERIFY_IS_EQUAL(tensor.data()[i], single_patch.data()[i]);
    }
  
    patch_dims[0] = 1;
    patch_dims[1] = 2;
    patch_dims[2] = 2;
    patch_dims[3] = 1;
    Tensor<float, 5, DataLayout> twod_patch;
    twod_patch = tensor.extract_patches(patch_dims);
  
    if (DataLayout == ColMajor) {
      VERIFY_IS_EQUAL(twod_patch.dimension(0), 1);
      VERIFY_IS_EQUAL(twod_patch.dimension(1), 2);
      VERIFY_IS_EQUAL(twod_patch.dimension(2), 2);
      VERIFY_IS_EQUAL(twod_patch.dimension(3), 1);
      VERIFY_IS_EQUAL(twod_patch.dimension(4), 2*2*4*7);
    } else {
      VERIFY_IS_EQUAL(twod_patch.dimension(0), 2*2*4*7);
      VERIFY_IS_EQUAL(twod_patch.dimension(1), 1);
      VERIFY_IS_EQUAL(twod_patch.dimension(2), 2);
      VERIFY_IS_EQUAL(twod_patch.dimension(3), 2);
      VERIFY_IS_EQUAL(twod_patch.dimension(4), 1);
    }
  
    for (int i = 0; i < 2; ++i) {
      for (int j = 0; j < 2; ++j) {
        for (int k = 0; k < 4; ++k) {
          for (int l = 0; l < 7; ++l) {
            int patch_loc;
            if (DataLayout == ColMajor) {
              patch_loc = i + 2 * (j + 2 * (k + 4 * l));
            } else {
              patch_loc = l + 7 * (k + 4 * (j + 2 * i));
            }
            for (int x = 0; x < 2; ++x) {
              for (int y = 0; y < 2; ++y) {
                if (DataLayout == ColMajor) {
                  VERIFY_IS_EQUAL(tensor(i,j+x,k+y,l), twod_patch(0,x,y,0,patch_loc));
                } else {
                  VERIFY_IS_EQUAL(tensor(i,j+x,k+y,l), twod_patch(patch_loc,0,x,y,0));
                }
              }
            }
          }
        }
      }
    }
  
    patch_dims[0] = 1;
    patch_dims[1] = 2;
    patch_dims[2] = 3;
    patch_dims[3] = 5;
    Tensor<float, 5, DataLayout> threed_patch;
    threed_patch = tensor.extract_patches(patch_dims);
  
    if (DataLayout == ColMajor) {
      VERIFY_IS_EQUAL(threed_patch.dimension(0), 1);
      VERIFY_IS_EQUAL(threed_patch.dimension(1), 2);
      VERIFY_IS_EQUAL(threed_patch.dimension(2), 3);
      VERIFY_IS_EQUAL(threed_patch.dimension(3), 5);
      VERIFY_IS_EQUAL(threed_patch.dimension(4), 2*2*3*3);
    } else {
      VERIFY_IS_EQUAL(threed_patch.dimension(0), 2*2*3*3);
      VERIFY_IS_EQUAL(threed_patch.dimension(1), 1);
      VERIFY_IS_EQUAL(threed_patch.dimension(2), 2);
      VERIFY_IS_EQUAL(threed_patch.dimension(3), 3);
      VERIFY_IS_EQUAL(threed_patch.dimension(4), 5);
    }
  
    for (int i = 0; i < 2; ++i) {
      for (int j = 0; j < 2; ++j) {
        for (int k = 0; k < 3; ++k) {
          for (int l = 0; l < 3; ++l) {
            int patch_loc;
            if (DataLayout == ColMajor) {
              patch_loc = i + 2 * (j + 2 * (k + 3 * l));
            } else {
              patch_loc = l + 3 * (k + 3 * (j + 2 * i));
            }
            for (int x = 0; x < 2; ++x) {
              for (int y = 0; y < 3; ++y) {
                for (int z = 0; z < 5; ++z) {
                  if (DataLayout == ColMajor) {
                    VERIFY_IS_EQUAL(tensor(i,j+x,k+y,l+z), threed_patch(0,x,y,z,patch_loc));
                  } else {
                    VERIFY_IS_EQUAL(tensor(i,j+x,k+y,l+z), threed_patch(patch_loc,0,x,y,z));
                  }
                }
              }
            }
          }
        }
      }
    }
  }
  
  void test_cxx11_tensor_patch()
  {
     CALL_SUBTEST(test_simple_patch<ColMajor>());
     CALL_SUBTEST(test_simple_patch<RowMajor>());
     //   CALL_SUBTEST(test_expr_shuffling());
  }
  