Return a diagonal matrix with vector v on diagonal k.
The second argument is optional. If it is positive, the vector is placed on the k-th superdiagonal. If it is negative, it is placed on the -k-th subdiagonal. The default value of k is 0, and the vector is placed on the main diagonal. For example:
diag ([1, 2, 3], 1)
⇒ 0 1 0 0
0 0 2 0
0 0 0 3
0 0 0 0
The 3-input form returns a diagonal matrix with vector v on the main diagonal and the resulting matrix being of size m rows x n columns.
Given a matrix argument, instead of a vector, diag extracts the
k-th diagonal of the matrix.
Package: communications