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      1 namespace Eigen {
      2 
      3 /** \eigenManualPage TutorialReshapeSlicing Reshape and Slicing
      4 
      5 %Eigen does not expose convenient methods to take slices or to reshape a matrix yet.
      6 Nonetheless, such features can easily be emulated using the Map class.
      7 
      8 \eigenAutoToc
      9 
     10 \section TutorialReshape Reshape
     11 
     12 A reshape operation consists in modifying the sizes of a matrix while keeping the same coefficients.
     13 Instead of modifying the input matrix itself, which is not possible for compile-time sizes, the approach consist in creating a different \em view on the storage using class Map.
     14 Here is a typical example creating a 1D linear view of a matrix:
     15 
     16 <table class="example">
     17 <tr><th>Example:</th><th>Output:</th></tr>
     18 <tr><td>
     19 \include Tutorial_ReshapeMat2Vec.cpp
     20 </td>
     21 <td>
     22 \verbinclude Tutorial_ReshapeMat2Vec.out
     23 </td></tr></table>
     24 
     25 Remark how the storage order of the input matrix modifies the order of the coefficients in the linear view.
     26 Here is another example reshaping a 2x6 matrix to a 6x2 one:
     27 <table class="example">
     28 <tr><th>Example:</th><th>Output:</th></tr>
     29 <tr><td>
     30 \include Tutorial_ReshapeMat2Mat.cpp
     31 </td>
     32 <td>
     33 \verbinclude Tutorial_ReshapeMat2Mat.out
     34 </td></tr></table>
     35 
     36 
     37 
     38 \section TutorialSlicing Slicing
     39 
     40 Slicing consists in taking a set of rows, columns, or elements, uniformly spaced within a matrix.
     41 Again, the class Map allows to easily mimic this feature.
     42 
     43 For instance, one can skip every P elements in a vector:
     44 <table class="example">
     45 <tr><th>Example:</th><th>Output:</th></tr>
     46 <tr><td>
     47 \include Tutorial_SlicingVec.cpp
     48 </td>
     49 <td>
     50 \verbinclude Tutorial_SlicingVec.out
     51 </td></tr></table>
     52 
     53 One can olso take one column over three using an adequate outer-stride or inner-stride depending on the actual storage order:
     54 <table class="example">
     55 <tr><th>Example:</th><th>Output:</th></tr>
     56 <tr><td>
     57 \include Tutorial_SlicingCol.cpp
     58 </td>
     59 <td>
     60 \verbinclude Tutorial_SlicingCol.out
     61 </td></tr></table>
     62 
     63 */
     64 
     65 }
     66