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67 lines
2.1 KiB
Plaintext
67 lines
2.1 KiB
Plaintext
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namespace Eigen {
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/** \eigenManualPage TutorialSTL STL iterators and algorithms
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Since the version 3.4, %Eigen's dense matrices and arrays provide STL compatible iterators.
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As demonstrated below, this makes them naturally compatible with range-for-loops and STL's algorithms.
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\eigenAutoToc
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\section TutorialSTLVectors Iterating over 1D arrays and vectors
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Any dense 1D expressions exposes the pair of `begin()/end()` methods to iterate over them.
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This directly enables c++11 range for loops:
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<table class="example">
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<tr><th>Example:</th><th>Output:</th></tr>
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<tr><td>
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\include Tutorial_range_for_loop_1d_cxx11.cpp
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</td>
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<td>
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\verbinclude Tutorial_range_for_loop_1d_cxx11.out
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</td></tr></table>
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One dimensional expressions can also easily be passed to STL algorithms:
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<table class="example">
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<tr><th>Example:</th><th>Output:</th></tr>
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<tr><td>
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\include Tutorial_std_sort.cpp
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</td>
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<td>
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\verbinclude Tutorial_std_sort.out
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</td></tr></table>
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Similar to `std::vector`, 1D expressions also exposes the pair of `cbegin()/cend()` methods to conveniently get const iterators on non-const object.
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\section TutorialSTLMatrices Iterating over coefficients of 2D arrays and matrices
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STL iterators are intrinsically designed to iterate over 1D structures.
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This is why `begin()/end()` methods are disabled for 2D expressions.
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Iterating over all coefficients of a 2D expressions is still easily accomplished by creating a 1D linear view through `reshaped()`:
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<table class="example">
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<tr><th>Example:</th><th>Output:</th></tr>
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<tr><td>
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\include Tutorial_range_for_loop_2d_cxx11.cpp
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</td>
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<td>
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\verbinclude Tutorial_range_for_loop_2d_cxx11.out
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</td></tr></table>
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\section TutorialSTLRowsColumns Iterating over rows or columns of 2D arrays and matrices
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It is also possible to get iterators over rows or columns of 2D expressions.
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Those are available through the `rowwise()` and `colwise()` proxies.
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Here is an example sorting each row of a matrix:
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<table class="example">
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<tr><th>Example:</th><th>Output:</th></tr>
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<tr><td>
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\include Tutorial_std_sort_rows.cpp
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</td>
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<td>
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\verbinclude Tutorial_std_sort_rows.out
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</td></tr></table>
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*/
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}
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