Function triangular_rect

dependence/eigen-3.4.0/test/triangular.cpp:178–258

template<typename MatrixType> void triangular_rect(const MatrixType& m)
{
  typedef typename MatrixType::Scalar Scalar;
  typedef typename NumTraits<Scalar>::Real RealScalar;
  enum { Rows =  MatrixType::RowsAtCompileTime, Cols =  MatrixType::ColsAtCompileTime };

  Index rows = m.rows();
  Index cols = m.cols();

  MatrixType m1 = MatrixType::Random(rows, cols),
             m2 = MatrixType::Random(rows, cols),
             m3(rows, cols),
             m4(rows, cols),
             r1(rows, cols),
             r2(rows, cols);

  MatrixType m1up = m1.template triangularView<Upper>();
  MatrixType m2up = m2.template triangularView<Upper>();

  if (rows>1 && cols>1)
  {
    VERIFY(m1up.isUpperTriangular());
    VERIFY(m2up.transpose().isLowerTriangular());
    VERIFY(!m2.isLowerTriangular());
  }

  // test overloaded operator+=
  r1.setZero();
  r2.setZero();
  r1.template triangularView<Upper>() +=  m1;
  r2 += m1up;
  VERIFY_IS_APPROX(r1,r2);

  // test overloaded operator=
  m1.setZero();
  m1.template triangularView<Upper>() = 3 * m2;
  m3 = 3 * m2;
  VERIFY_IS_APPROX(m3.template triangularView<Upper>().toDenseMatrix(), m1);


  m1.setZero();
  m1.template triangularView<Lower>() = 3 * m2;
  VERIFY_IS_APPROX(m3.template triangularView<Lower>().toDenseMatrix(), m1);

  m1.setZero();
  m1.template triangularView<StrictlyUpper>() = 3 * m2;
  VERIFY_IS_APPROX(m3.template triangularView<StrictlyUpper>().toDenseMatrix(), m1);


  m1.setZero();
  m1.template triangularView<StrictlyLower>() = 3 * m2;
  VERIFY_IS_APPROX(m3.template triangularView<StrictlyLower>().toDenseMatrix(), m1);
  m1.setRandom();
  m2 = m1.template triangularView<Upper>();
  VERIFY(m2.isUpperTriangular());
  VERIFY(!m2.isLowerTriangular());
  m2 = m1.template triangularView<StrictlyUpper>();
  VERIFY(m2.isUpperTriangular());