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: -
+Any memory buffer can be mapped as an Eigen expression using the Map() static method: \code std::vector stlarray(10); -Map(&stlarray[0], stlarray.size()).setOnes(); -int data[4] = 1, 2, 3, 4; -Matrix2i mat2x2(data); -MatrixXi mat2x2 = Map(data); -MatrixXi mat2x2 = Map(data,2,2); +VectorXf::Map(&stlarray[0], stlarray.size()).squaredNorm(); +\endcode +Here VectorXf::Map returns an object of class Map, 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 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 m(array); +Matrix3d::Map(array).setIdentity(); \endcode -
- \subsection TutorialCommaInit Comma initializer