Using the C++ Math Library

Assigning to a Subarray

Use two vector indices to generate a matrix destination. For example, let the vector index B equal 1 2, and the vector index C equal 2 3. Then,

A(B,C) = vertcat(horzcat(1, 4) horzcat(3, 2));

copies a 2-by-2 matrix into the second and third columns of rows 1 and 2: the upper right corner of A. The example matrix A becomes:

1 1 4
2 3 2
3 6 9

You can also use a logical matrix as an index. For example, let B be the logical matrix:

0 1 1
0 1 1
0 0 0

Then,

A(B) = vertcat(horzcat(1, 4) horzcat(3, 2));

changes A to:

1 1 4
2 3 2
3 6 9

Assigning to a Multiple Elements

Assigning to All Elements