eigen/test/reshape.cpp

// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2017 Gael Guennebaud <gael.guennebaud@inria.fr>
// Copyright (C) 2014 yoco <peter.xiau@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"

using Eigen::placeholders::all;
using Eigen::placeholders::last;

template <typename T1, typename T2>
std::enable_if_t<internal::is_same<T1, T2>::value, bool> is_same_eq(const T1& a, const T2& b) {
  return (a.array() == b.array()).all();
}

template <int Order, typename MatType>
void check_auto_reshape4x4(MatType m) {
  internal::VariableAndFixedInt<MatType::SizeAtCompileTime == Dynamic ? -1 : 1> v1(1);
  internal::VariableAndFixedInt<MatType::SizeAtCompileTime == Dynamic ? -1 : 2> v2(2);
  internal::VariableAndFixedInt<MatType::SizeAtCompileTime == Dynamic ? -1 : 4> v4(4);
  internal::VariableAndFixedInt<MatType::SizeAtCompileTime == Dynamic ? -1 : 8> v8(8);
  internal::VariableAndFixedInt<MatType::SizeAtCompileTime == Dynamic ? -1 : 16> v16(16);

  VERIFY(is_same_eq(m.template reshaped<Order>(1, AutoSize), m.template reshaped<Order>(1, 16)));
  VERIFY(is_same_eq(m.template reshaped<Order>(AutoSize, 16), m.template reshaped<Order>(1, 16)));
  VERIFY(is_same_eq(m.template reshaped<Order>(2, AutoSize), m.template reshaped<Order>(2, 8)));
  VERIFY(is_same_eq(m.template reshaped<Order>(AutoSize, 8), m.template reshaped<Order>(2, 8)));
  VERIFY(is_same_eq(m.template reshaped<Order>(4, AutoSize), m.template reshaped<Order>(4, 4)));
  VERIFY(is_same_eq(m.template reshaped<Order>(AutoSize, 4), m.template reshaped<Order>(4, 4)));
  VERIFY(is_same_eq(m.template reshaped<Order>(8, AutoSize), m.template reshaped<Order>(8, 2)));
  VERIFY(is_same_eq(m.template reshaped<Order>(AutoSize, 2), m.template reshaped<Order>(8, 2)));
  VERIFY(is_same_eq(m.template reshaped<Order>(16, AutoSize), m.template reshaped<Order>(16, 1)));
  VERIFY(is_same_eq(m.template reshaped<Order>(AutoSize, 1), m.template reshaped<Order>(16, 1)));

  VERIFY(is_same_eq(m.template reshaped<Order>(fix<1>, AutoSize), m.template reshaped<Order>(fix<1>, v16)));
  VERIFY(is_same_eq(m.template reshaped<Order>(AutoSize, fix<16>), m.template reshaped<Order>(v1, fix<16>)));
  VERIFY(is_same_eq(m.template reshaped<Order>(fix<2>, AutoSize), m.template reshaped<Order>(fix<2>, v8)));
  VERIFY(is_same_eq(m.template reshaped<Order>(AutoSize, fix<8>), m.template reshaped<Order>(v2, fix<8>)));
  VERIFY(is_same_eq(m.template reshaped<Order>(fix<4>, AutoSize), m.template reshaped<Order>(fix<4>, v4)));
  VERIFY(is_same_eq(m.template reshaped<Order>(AutoSize, fix<4>), m.template reshaped<Order>(v4, fix<4>)));
  VERIFY(is_same_eq(m.template reshaped<Order>(fix<8>, AutoSize), m.template reshaped<Order>(fix<8>, v2)));
  VERIFY(is_same_eq(m.template reshaped<Order>(AutoSize, fix<2>), m.template reshaped<Order>(v8, fix<2>)));
  VERIFY(is_same_eq(m.template reshaped<Order>(fix<16>, AutoSize), m.template reshaped<Order>(fix<16>, v1)));
  VERIFY(is_same_eq(m.template reshaped<Order>(AutoSize, fix<1>), m.template reshaped<Order>(v16, fix<1>)));
}

template <typename MatType>
void check_direct_access_reshape4x4(MatType, internal::FixedInt<RowMajorBit>) {}

template <typename MatType>
void check_direct_access_reshape4x4(MatType m, internal::FixedInt<0>) {
  VERIFY_IS_EQUAL(m.reshaped(1, 16).data(), m.data());
  VERIFY_IS_EQUAL(m.reshaped(1, 16).innerStride(), 1);

  VERIFY_IS_EQUAL(m.reshaped(2, 8).data(), m.data());
  VERIFY_IS_EQUAL(m.reshaped(2, 8).innerStride(), 1);
  VERIFY_IS_EQUAL(m.reshaped(2, 8).outerStride(), 2);
}

// just test a 4x4 matrix, enumerate all combination manually
template <typename MatType>
void reshape4x4(MatType m) {
  typedef typename MatType::Scalar Scalar;

  internal::VariableAndFixedInt<MatType::SizeAtCompileTime == Dynamic ? -1 : 1> v1(1);
  internal::VariableAndFixedInt<MatType::SizeAtCompileTime == Dynamic ? -1 : 2> v2(2);
  internal::VariableAndFixedInt<MatType::SizeAtCompileTime == Dynamic ? -1 : 4> v4(4);
  internal::VariableAndFixedInt<MatType::SizeAtCompileTime == Dynamic ? -1 : 8> v8(8);
  internal::VariableAndFixedInt<MatType::SizeAtCompileTime == Dynamic ? -1 : 16> v16(16);

  if ((MatType::Flags & RowMajorBit) == 0) {
    typedef Map<MatrixXi> MapMat;
    // dynamic
    VERIFY_IS_EQUAL((m.reshaped(1, 16)), MapMat(m.data(), 1, 16));
    VERIFY_IS_EQUAL((m.reshaped(2, 8)), MapMat(m.data(), 2, 8));
    VERIFY_IS_EQUAL((m.reshaped(4, 4)), MapMat(m.data(), 4, 4));
    VERIFY_IS_EQUAL((m.reshaped(8, 2)), MapMat(m.data(), 8, 2));
    VERIFY_IS_EQUAL((m.reshaped(16, 1)), MapMat(m.data(), 16, 1));

    // static
    VERIFY_IS_EQUAL(m.reshaped(fix<1>, fix<16>), MapMat(m.data(), 1, 16));
    VERIFY_IS_EQUAL(m.reshaped(fix<2>, fix<8>), MapMat(m.data(), 2, 8));
    VERIFY_IS_EQUAL(m.reshaped(fix<4>, fix<4>), MapMat(m.data(), 4, 4));
    VERIFY_IS_EQUAL(m.reshaped(fix<8>, fix<2>), MapMat(m.data(), 8, 2));
    VERIFY_IS_EQUAL(m.reshaped(fix<16>, fix<1>), MapMat(m.data(), 16, 1));

    // reshape chain
    VERIFY_IS_EQUAL((m.reshaped(1, 16)
                         .reshaped(fix<2>, fix<8>)
                         .reshaped(16, 1)
                         .reshaped(fix<8>, fix<2>)
                         .reshaped(2, 8)
                         .reshaped(fix<1>, fix<16>)
                         .reshaped(4, 4)
                         .reshaped(fix<16>, fix<1>)
                         .reshaped(8, 2)
                         .reshaped(fix<4>, fix<4>)),
                    MapMat(m.data(), 4, 4));
  }

  VERIFY(is_same_eq(m.reshaped(1, AutoSize), m.reshaped(1, 16)));
  VERIFY(is_same_eq(m.reshaped(AutoSize, 16), m.reshaped(1, 16)));
  VERIFY(is_same_eq(m.reshaped(2, AutoSize), m.reshaped(2, 8)));
  VERIFY(is_same_eq(m.reshaped(AutoSize, 8), m.reshaped(2, 8)));
  VERIFY(is_same_eq(m.reshaped(4, AutoSize), m.reshaped(4, 4)));
  VERIFY(is_same_eq(m.reshaped(AutoSize, 4), m.reshaped(4, 4)));
  VERIFY(is_same_eq(m.reshaped(8, AutoSize), m.reshaped(8, 2)));
  VERIFY(is_same_eq(m.reshaped(AutoSize, 2), m.reshaped(8, 2)));
  VERIFY(is_same_eq(m.reshaped(16, AutoSize), m.reshaped(16, 1)));
  VERIFY(is_same_eq(m.reshaped(AutoSize, 1), m.reshaped(16, 1)));

  VERIFY(is_same_eq(m.reshaped(fix<1>, AutoSize), m.reshaped(fix<1>, v16)));
  VERIFY(is_same_eq(m.reshaped(AutoSize, fix<16>), m.reshaped(v1, fix<16>)));
  VERIFY(is_same_eq(m.reshaped(fix<2>, AutoSize), m.reshaped(fix<2>, v8)));
  VERIFY(is_same_eq(m.reshaped(AutoSize, fix<8>), m.reshaped(v2, fix<8>)));
  VERIFY(is_same_eq(m.reshaped(fix<4>, AutoSize), m.reshaped(fix<4>, v4)));
  VERIFY(is_same_eq(m.reshaped(AutoSize, fix<4>), m.reshaped(v4, fix<4>)));
  VERIFY(is_same_eq(m.reshaped(fix<8>, AutoSize), m.reshaped(fix<8>, v2)));
  VERIFY(is_same_eq(m.reshaped(AutoSize, fix<2>), m.reshaped(v8, fix<2>)));
  VERIFY(is_same_eq(m.reshaped(fix<16>, AutoSize), m.reshaped(fix<16>, v1)));
  VERIFY(is_same_eq(m.reshaped(AutoSize, fix<1>), m.reshaped(v16, fix<1>)));

  check_auto_reshape4x4<ColMajor>(m);
  check_auto_reshape4x4<RowMajor>(m);
  check_auto_reshape4x4<AutoOrder>(m);
  check_auto_reshape4x4<ColMajor>(m.transpose());
  check_auto_reshape4x4<ColMajor>(m.transpose());
  check_auto_reshape4x4<AutoOrder>(m.transpose());

  check_direct_access_reshape4x4(m, fix<MatType::Flags & RowMajorBit>);

  if ((MatType::Flags & RowMajorBit) == 0) {
    VERIFY_IS_EQUAL(m.template reshaped<ColMajor>(2, 8), m.reshaped(2, 8));
    VERIFY_IS_EQUAL(m.template reshaped<ColMajor>(2, 8), m.template reshaped<AutoOrder>(2, 8));
    VERIFY_IS_EQUAL(m.transpose().template reshaped<RowMajor>(2, 8), m.transpose().template reshaped<AutoOrder>(2, 8));
  } else {
    VERIFY_IS_EQUAL(m.template reshaped<ColMajor>(2, 8), m.reshaped(2, 8));
    VERIFY_IS_EQUAL(m.template reshaped<RowMajor>(2, 8), m.template reshaped<AutoOrder>(2, 8));
    VERIFY_IS_EQUAL(m.transpose().template reshaped<ColMajor>(2, 8), m.transpose().template reshaped<AutoOrder>(2, 8));
    VERIFY_IS_EQUAL(m.transpose().reshaped(2, 8), m.transpose().template reshaped<AutoOrder>(2, 8));
  }

  MatrixXi m28r1 = m.template reshaped<RowMajor>(2, 8);
  MatrixXi m28r2 = m.transpose().template reshaped<ColMajor>(8, 2).transpose();
  VERIFY_IS_EQUAL(m28r1, m28r2);

  VERIFY(is_same_eq(m.reshaped(v16, fix<1>), m.reshaped()));
  VERIFY_IS_EQUAL(m.reshaped(16, 1).eval(), m.reshaped().eval());
  VERIFY_IS_EQUAL(m.reshaped(1, 16).eval(), m.reshaped().transpose().eval());
  VERIFY_IS_EQUAL(m.reshaped().reshaped(2, 8), m.reshaped(2, 8));
  VERIFY_IS_EQUAL(m.reshaped().reshaped(4, 4), m.reshaped(4, 4));
  VERIFY_IS_EQUAL(m.reshaped().reshaped(8, 2), m.reshaped(8, 2));

  VERIFY_IS_EQUAL(m.reshaped(), m.template reshaped<ColMajor>());
  VERIFY_IS_EQUAL(m.transpose().reshaped(), m.template reshaped<RowMajor>());
  VERIFY_IS_EQUAL(m.template reshaped<RowMajor>(AutoSize, fix<1>), m.template reshaped<RowMajor>());
  VERIFY_IS_EQUAL(m.template reshaped<AutoOrder>(AutoSize, fix<1>), m.template reshaped<AutoOrder>());

  VERIFY(is_same_eq(m.reshaped(AutoSize, fix<1>), m.reshaped()));
  VERIFY_IS_EQUAL(m.template reshaped<RowMajor>(fix<1>, AutoSize), m.transpose().reshaped().transpose());

  // check assignment
  {
    Matrix<Scalar, Dynamic, 1> m1x(m.size());
    m1x.setRandom();
    VERIFY_IS_APPROX(m.reshaped() = m1x, m1x);
    VERIFY_IS_APPROX(m, m1x.reshaped(4, 4));

    Matrix<Scalar, Dynamic, Dynamic> m28(2, 8);
    m28.setRandom();
    VERIFY_IS_APPROX(m.reshaped(2, 8) = m28, m28);
    VERIFY_IS_APPROX(m, m28.reshaped(4, 4));
    VERIFY_IS_APPROX(m.template reshaped<RowMajor>(2, 8) = m28, m28);

    Matrix<Scalar, Dynamic, Dynamic> m24(2, 4);
    m24.setRandom();
    VERIFY_IS_APPROX(m(seq(0, last, 2), all).reshaped(2, 4) = m24, m24);

    // check constness:
    m.reshaped(2, 8).nestedExpression() = m;
  }
}

template <typename BlockType>
void reshape_block(const BlockType& M) {
  auto dense = M.eval();
  Index rows = M.size() / 2;
  Index cols = M.size() / rows;
  VERIFY_IS_EQUAL(dense.reshaped(rows, cols), M.reshaped(rows, cols));

  for (Index i = 0; i < rows; ++i) {
    VERIFY_IS_EQUAL(dense.reshaped(rows, cols).row(i), M.reshaped(rows, cols).row(i));
  }

  for (Index j = 0; j < cols; ++j) {
    VERIFY_IS_EQUAL(dense.reshaped(rows, cols).col(j), M.reshaped(rows, cols).col(j));
  }
}

EIGEN_DECLARE_TEST(reshape) {
  typedef Matrix<int, Dynamic, Dynamic, RowMajor> RowMatrixXi;
  typedef Matrix<int, 4, 4, RowMajor> RowMatrix4i;
  MatrixXi mx = MatrixXi::Random(4, 4);
  Matrix4i m4 = Matrix4i::Random(4, 4);
  RowMatrixXi rmx = RowMatrixXi::Random(4, 4);
  RowMatrix4i rm4 = RowMatrix4i::Random(4, 4);

  // test dynamic-size matrix
  CALL_SUBTEST(reshape4x4(mx));
  // test static-size matrix
  CALL_SUBTEST(reshape4x4(m4));
  // test dynamic-size const matrix
  CALL_SUBTEST(reshape4x4(static_cast<const MatrixXi>(mx)));
  // test static-size const matrix
  CALL_SUBTEST(reshape4x4(static_cast<const Matrix4i>(m4)));

  CALL_SUBTEST(reshape4x4(rmx));
  CALL_SUBTEST(reshape4x4(rm4));
  CALL_SUBTEST(reshape_block(rm4.col(1)));
}