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author | Jitse Niesen <jitse@maths.leeds.ac.uk> | 2014-09-27 23:25:58 +0100 |
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committer | Jitse Niesen <jitse@maths.leeds.ac.uk> | 2014-09-27 23:25:58 +0100 |
commit | ce2035af868d57b85b4078c15843d5c1f51047dc (patch) | |
tree | ca6392457ba02fa24e8f5f0ddcf755697d73d36e /doc/examples/make_circulant.cpp.evaluator | |
parent | 6d0f0b8cecd0ee944503d885fd34278044bab746 (diff) |
New doc page on implementing a new expression class.
Diffstat (limited to 'doc/examples/make_circulant.cpp.evaluator')
-rw-r--r-- | doc/examples/make_circulant.cpp.evaluator | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/doc/examples/make_circulant.cpp.evaluator b/doc/examples/make_circulant.cpp.evaluator new file mode 100644 index 000000000..98713cdc0 --- /dev/null +++ b/doc/examples/make_circulant.cpp.evaluator @@ -0,0 +1,33 @@ +namespace Eigen { + namespace internal { + template<typename ArgType> + struct evaluator<Circulant<ArgType> > + : evaluator_base<Circulant<ArgType> > + { + typedef Circulant<ArgType> XprType; + typedef typename nested_eval<ArgType, XprType::ColsAtCompileTime>::type ArgTypeNested; + typedef typename remove_all<ArgTypeNested>::type ArgTypeNestedCleaned; + typedef typename XprType::CoeffReturnType CoeffReturnType; + typedef typename XprType::Index Index; + + enum { + CoeffReadCost = evaluator<ArgTypeNestedCleaned>::CoeffReadCost, + Flags = Eigen::ColMajor + }; + + evaluator(const XprType& xpr) + : m_argImpl(xpr.m_arg), m_rows(xpr.rows()) + { } + + CoeffReturnType coeff(Index row, Index col) const + { + Index index = row - col; + if (index < 0) index += m_rows; + return m_argImpl.coeff(index); + } + + typename evaluator<ArgTypeNestedCleaned>::nestedType m_argImpl; + const Index m_rows; + }; + } +} |