diff options
author | Benoit Jacob <jacob.benoit.1@gmail.com> | 2009-10-31 14:37:11 -0400 |
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committer | Benoit Jacob <jacob.benoit.1@gmail.com> | 2009-10-31 14:37:11 -0400 |
commit | 5ba19a53a6eb68c0bf1d2b531fe7fbffcca39929 (patch) | |
tree | 515611a3eff08d401a7266363aa36f6a18b2cf3a /doc | |
parent | 3ae4e3880febfa7a1948bc8accdabe066d17344d (diff) |
rephrase tutorial on Map
Diffstat (limited to 'doc')
-rw-r--r-- | doc/C01_QuickStartGuide.dox | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/doc/C01_QuickStartGuide.dox b/doc/C01_QuickStartGuide.dox index 2943aed80..06b2595e7 100644 --- a/doc/C01_QuickStartGuide.dox +++ b/doc/C01_QuickStartGuide.dox @@ -278,18 +278,24 @@ Of course, fixed-size matrices can't be resized. \subsection TutorialMap Map -Any memory buffer can be mapped as an Eigen expression: -<table class="tutorial_code"><tr><td> +Any memory buffer can be mapped as an Eigen expression using the Map() static method: \code std::vector<float> stlarray(10); -Map<VectorXf>(&stlarray[0], stlarray.size()).setOnes(); -int data[4] = 1, 2, 3, 4; -Matrix2i mat2x2(data); -MatrixXi mat2x2 = Map<Matrix2i>(data); -MatrixXi mat2x2 = Map<MatrixXi>(data,2,2); +VectorXf::Map(&stlarray[0], stlarray.size()).squaredNorm(); +\endcode +Here VectorXf::Map returns an object of class Map<VectorXf>, which behaves like a VectorXf except that it uses the existing array. You can write to this object, that will write to the existing array. You can also construct a named obtect to reuse it: +\code +float array[rows*cols]; +Map<MatrixXf> m(array,rows,cols); +m = othermatrix1 * othermatrix2; +m.eigenvalues(); +\endcode +In the fixed-size case, no need to pass sizes: +\code +float array[9]; +Map<Matrix3d> m(array); +Matrix3d::Map(array).setIdentity(); \endcode -</td></tr></table> - \subsection TutorialCommaInit Comma initializer |