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Diffstat (limited to 'doc/examples/class_Block.cpp')
-rw-r--r-- | doc/examples/class_Block.cpp | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/doc/examples/class_Block.cpp b/doc/examples/class_Block.cpp new file mode 100644 index 000000000..17dc4bce1 --- /dev/null +++ b/doc/examples/class_Block.cpp @@ -0,0 +1,23 @@ +#include <Eigen/Core.h> +USING_PART_OF_NAMESPACE_EIGEN +using namespace std; + +template<typename Scalar, typename Derived> +Eigen::Block<Derived, 2, 2> +topLeft2x2Corner(MatrixBase<Scalar, Derived>& m) +{ + return Eigen::Block<Derived, 2, 2>(m.ref(), 0, 0); + // note: tempting as it is, writing "m.block<2,2>(0,0)" here + // causes a compile error with g++ 4.2, apparently due to + // g++ getting confused by the many template types and + // template arguments involved. +} + +int main(int, char**) +{ + Matrix3d m = Matrix3d::identity(); + cout << topLeft2x2Corner(m) << endl; + topLeft2x2Corner(m) *= 2; + cout << "Now the matrix m is:" << endl << m << endl; + return 0; +} |