Function diagonal

dependence/eigen-3.4.0/test/diagonal.cpp:12–71

#include "main.h"

template<typename MatrixType> void diagonal(const MatrixType& m)
{
  typedef typename MatrixType::Scalar Scalar;

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

  MatrixType m1 = MatrixType::Random(rows, cols),
             m2 = MatrixType::Random(rows, cols);

  Scalar s1 = internal::random<Scalar>();

  //check diagonal()
  VERIFY_IS_APPROX(m1.diagonal(), m1.transpose().diagonal());
  m2.diagonal() = 2 * m1.diagonal();
  m2.diagonal()[0] *= 3;

  if (rows>2)
  {
    enum {
      N1 = MatrixType::RowsAtCompileTime>2 ?  2 : 0,
      N2 = MatrixType::RowsAtCompileTime>1 ? -1 : 0
    };

    // check sub/super diagonal
    if(MatrixType::SizeAtCompileTime!=Dynamic)
    {
      VERIFY(m1.template diagonal<N1>().RowsAtCompileTime == m1.diagonal(N1).size());
      VERIFY(m1.template diagonal<N2>().RowsAtCompileTime == m1.diagonal(N2).size());
    }

    m2.template diagonal<N1>() = 2 * m1.template diagonal<N1>();
    VERIFY_IS_APPROX(m2.template diagonal<N1>(), static_cast<Scalar>(2) * m1.diagonal(N1));
    m2.template diagonal<N1>()[0] *= 3;
    VERIFY_IS_APPROX(m2.template diagonal<N1>()[0], static_cast<Scalar>(6) * m1.template diagonal<N1>()[0]);


    m2.template diagonal<N2>() = 2 * m1.template diagonal<N2>();
    m2.template diagonal<N2>()[0] *= 3;
    VERIFY_IS_APPROX(m2.template diagonal<N2>()[0], static_cast<Scalar>(6) * m1.template diagonal<N2>()[0]);

    m2.diagonal(N1) = 2 * m1.diagonal(N1);
    VERIFY_IS_APPROX(m2.template diagonal<N1>(), static_cast<Scalar>(2) * m1.diagonal(N1));
    m2.diagonal(N1)[0] *= 3;
    VERIFY_IS_APPROX(m2.diagonal(N1)[0], static_cast<Scalar>(6) * m1.diagonal(N1)[0]);

    m2.diagonal(N2) = 2 * m1.diagonal(N2);
    VERIFY_IS_APPROX(m2.template diagonal<N2>(), static_cast<Scalar>(2) * m1.diagonal(N2));
    m2.diagonal(N2)[0] *= 3;
    VERIFY_IS_APPROX(m2.diagonal(N2)[0], static_cast<Scalar>(6) * m1.diagonal(N2)[0]);

    m2.diagonal(N2).x() = s1;
    VERIFY_IS_APPROX(m2.diagonal(N2).x(), s1);
    m2.diagonal(N2).coeffRef(0) = Scalar(2)*s1;
    VERIFY_IS_APPROX(m2.diagonal(N2).coeff(0), Scalar(2)*s1);
  }

  VERIFY( m1.diagonal( cols).size()==0 );