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authorGravatar Gael Guennebaud <g.gael@free.fr>2019-01-22 17:08:47 +0100
committerGravatar Gael Guennebaud <g.gael@free.fr>2019-01-22 17:08:47 +0100
commit80f81f9c4b01cc4f513c5b92c52c5a0efb68ecc3 (patch)
tree6e9c61e63dcb690afb48f40e1d470ed2c735ceff /doc/TutorialMatrixClass.dox
parentdb152b9ee6effd3799f70a621f495c427cb3c33f (diff)
Cleanup SFINAE in Array/Matrix(initializer_list) ctors and minor doc editing.
Diffstat (limited to 'doc/TutorialMatrixClass.dox')
-rw-r--r--doc/TutorialMatrixClass.dox29
1 files changed, 15 insertions, 14 deletions
diff --git a/doc/TutorialMatrixClass.dox b/doc/TutorialMatrixClass.dox
index fc0ce5b1e..c44c8f24f 100644
--- a/doc/TutorialMatrixClass.dox
+++ b/doc/TutorialMatrixClass.dox
@@ -101,38 +101,39 @@ Matrix3f a(3,3);
\endcode
and is a no-operation.
-Additionally, we also offer some constructors to initialize the coefficients of small fixed-size vectors up to size 4:
+Matrices and vectors can also be initialized from lists of coefficients.
+Prior to C++11, this feature is limited to small fixed-size column or vectors up to size 4:
\code
Vector2d a(5.0, 6.0);
Vector3d b(5.0, 6.0, 7.0);
Vector4d c(5.0, 6.0, 7.0, 8.0);
\endcode
-If C++11 is enabled, matrices can be constructed and initialized using initializer lists. In the case of fixed-sized vectors
-and rowvectors a simple initializer list can be passed:
+If C++11 is enabled, fixed-size column or row vectors of arbitrary size can be initialized through a single initializer list (\link Matrix::Matrix(const std::initializer_list<Scalar>&) details \endlink):
\code
-Vector2i a {1, 2}; // A vector containing the elements {1, 2}
-Matrix<int, 4, 1> b {1, 2, 3, 4}; // A row-vector containing the elements {1, 2, 3, 4}
-Matrix<int, 1, 4> c {1, 2, 3, 4}; // A vector containing the elements {1, 2, 3, 4}
+Vector2i a {1, 2}; // A column vector containing the elements {1, 2}
+Matrix<int, 5, 1> b {1, 2, 3, 4, 5}; // A row-vector containing the elements {1, 2, 3, 4, 5}
+Matrix<int, 1, 5> c {1, 2, 3, 4, 5}; // A column vector containing the elements {1, 2, 3, 4, 5}
\endcode
-In the case of fixed or dynamically sized matrices an initializer list containing an initializer list for each row
-can be passed. If the matrix is fixed-sized, the number of elements that are passed must match the dimensions.
+In the general case of matrices and vectors with either fixed or runtime sizes,
+coefficients have to be grouped by rows and passed as an initializer list of initializer list (\link Matrix::Matrix(const std::initializer_list<std::initializer_list<Scalar>>&) details \endlink):
\code
-MatrixXi a {
+MatrixXi a { // construct a 2x2 matrix
{1, 2}, // first row
{3, 4} // second row
};
Matrix<double, 2, 3> b {
- {2.0, 3.0, 4.0},
- {5.0, 6.0, 7.0},
+ {2, 3, 4},
+ {5, 6, 7},
};
\endcode
-In the case of vectors and rowvectors, the following shorthand notation can be used:
+For column or row vectors, implicit transposition is allowed.
+This means that a column vector can be initialized from a single row:
\code
-VectorXd a {{1.5, 2.5, 3.5}}; // A vector with 3 rows
-RowVectorXd b {{1.0, 2.0, 3.0, 4.0}}; // A rowvector with 4 columns
+VectorXd a {{1.5, 2.5, 3.5}}; // A column-vector with 3 coefficients
+RowVectorXd b {{1.0, 2.0, 3.0, 4.0}}; // A row-vector with 4 coefficients
\endcode
\section TutorialMatrixCoeffAccessors Coefficient accessors