The BLOCK function forms a block-diagonal matrix. The blocks are defined by the arguments to the function. Up to 15 matrices can be specified. The matrices are combined diagonally to form a new matrix.

For example, if , , and are any matrices, then the block matrix formed from these matrices has the following form:

The following statements produce a block-diagonal matrix composed of three blocks, shown in Figure 23.50:

a = 1;
b = {2 2,
     3 3};
c = {4 4 4,
     5 5 5};
d = block(a, b, c);
print d;