Matrix<T,N> is an N-dimensional matrix of some value type T. It can be used like this:
// zero dimensions: a scalar
Matrix<double ,0> m0 {1};
// one dimension: a vector (4 elements)
Matrix<double ,1> m1 {1,2,3,4};
// two dimensions (4*3 elements)
Matrix<double ,2> m2 {
{00,01,02,03}, // row 0
{10,11,12,13}, // row 1
{20,21,22,23} // row 2
};
// 3-by-2 matrix of 2-by-2 matrices
// a matrix is a plausible "number"
Matrix<Matrix<int,2>,2> mm {
{ // row 0
{{1, 2}, {3, 4}}, // col 0
{{4, 5}, {6, 7}}, // col 1
},
{ // row 1
{{8, 9}, {0, 1}}, // col 0
{{2, 3}, {4, 5}}, // col 1
},
{ // row 2
{{1, 2}, {3, 4}}, // col 0
{{4, 5}, {6, 7}}, // col 1
}
};
// three dimensions (4*7*9 elements), all 0-initialized
Matrix<double ,3> m3(4,7,9);
// 17 dimensions (no elements so far)
Matrix<complex<double>,17> m17;
A Matrix can be accessed through subscripting (to elements or rows), through rows and columns, or through slices (parts of rows or columns).
| Sytanx | Meaning |
|---|---|
| m.row(i) | Row i of m; a Matrix_ref<T,N−1> |
| m.column(i) | Column i of m; a Matrix_ref<T,N−1> |
| m[i] | C-style subscripting: m.row(i) |
| m(i,j) | Fortran-style element access: m[i][j]; a T&; the number of subscripts must be N |
| m(slice(i,n),slice(j)) | Submatrix access with slicing: a Matrix_ref<T,N>; slice(i,n) is elements [i:i+n) of the subscript’s dimension; slice(j) is elements [i:max) of the subscript’s dimension; max is the dimension’s extent; the number of subscripts must be N |