/usr/include/dune/common/identitymatrix.hh is in libdune-common-dev 2.3.1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 | #ifndef DUNE_COMMON_IDENTITYMATRIX_HH
#define DUNE_COMMON_IDENTITYMATRIX_HH
#include <dune/common/fmatrix.hh>
#include <dune/common/ftraits.hh>
#include <dune/common/math.hh>
#include <dune/common/std/constexpr.hh>
/**
* \file
* \ingroup DenseMatVec
* \brief Implementation of an identity matrix that does not store
* any data.
* \author Christoph Gersbacher
*/
namespace Dune
{
// IdentityMatrix
// --------------
/** \class IdentityMatrix
*
* \ingroup DenseMatVec
*
* \brief Read-only identity matrix.
*
* Implementation of an identity matrix that does not store any data.
*
* \tparam K field type
* \tparam N dimension
*/
template< class K, int N >
struct IdentityMatrix
{
/** \brief field type */
typedef K field_type;
/** \brief size type */
typedef std::size_t size_type;
/** \brief return number of rows */
DUNE_CONSTEXPR size_type rows () const { return N; }
/** \brief return number of columns */
DUNE_CONSTEXPR size_type cols () const { return N; }
/** \copydoc Dune::DenseMatrix::mv */
template< class X, class Y >
void mv ( const X &x, Y &y ) const
{
y = x;
}
/** \copydoc Dune::DenseMatrix::mtv */
template< class X, class Y >
void mtv ( const X &x, Y &y ) const
{
y = x;
}
/** \copydoc Dune::DenseMatrix::umv */
template< class X, class Y >
void umv ( const X &x, Y &y ) const
{
y += x;
}
/** \copydoc Dune::DenseMatrix::umtv */
template< class X, class Y >
void umtv ( const X &x, Y &y ) const
{
y += x;
}
/** \copydoc Dune::DenseMatrix::umhv */
template< class X, class Y >
void umhv ( const X &x, Y &y ) const
{
y += x;
}
/** \copydoc Dune::DenseMatrix::mmv */
template< class X, class Y >
void mmv ( const X &x, Y &y ) const
{
y -= x;
}
/** \copydoc Dune::DenseMatrix::mmtv */
template< class X, class Y >
void mmtv ( const X &x, Y &y ) const
{
y -= x;
}
/** \copydoc Dune::DenseMatrix::mmhv */
template< class X, class Y >
void mmhv ( const X &x, Y &y ) const
{
y -= x;
}
/** \copydoc Dune::DenseMatrix::usmv */
template< class X, class Y >
void usmv ( const field_type &alpha, const X &x, Y &y ) const
{
y.axpy( alpha, x );
}
/** \copydoc Dune::DenseMatrix::usmtv */
template< class X, class Y >
void usmtv ( const field_type &alpha, const X &x, Y &y ) const
{
y.axpy( alpha, x );
}
/** \copydoc Dune::DenseMatrix::usmhv */
template< class X, class Y >
void usmhv ( const field_type &alpha, const X &x, Y &y ) const
{
y.axpy( alpha, x );
}
/** \copydoc Dune::DenseMatrix::frobenius_norm */
typename FieldTraits< field_type >::real_type frobenius_norm () const
{
return std::sqrt( frobenius_norm2() );
}
/** \copydoc Dune::DenseMatrix::frobenius_norm2 */
typename FieldTraits< field_type >::real_type frobenius_norm2 () const
{
return FieldTraits< field_type >::real_type( N );
}
/** \copydoc Dune::DenseMatrix::infinity_norm */
typename FieldTraits< field_type >::real_type infinity_norm () const
{
return FieldTraits< field_type >::real_type( 1 );
}
/** \copydoc Dune::DenseMatrix::infinity_norm_real */
typename FieldTraits< field_type >::real_type infinity_norm_real () const
{
return FieldTraits< field_type >::real_type( 1 );
}
/** \brief cast to FieldMatrix */
operator FieldMatrix< field_type, N, N > () const
{
FieldMatrix< field_type, N, N > fieldMatrix( 0 );
for( int i = 0; i < N; ++i )
fieldMatrix[ i ][ i ] = field_type( 1 );
return fieldMatrix;
}
};
} // namespace Dune
#endif // #ifndef DUNE_COMMON_IDENTITYMATRIX_HH
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