How can I create a triangular matrix based on a vector, in MATLAB?

Question

Let\'s say I\'ve got a vector like this one:

A = [101:105]

Which is really:

[ 101, 102, 103, 104, 105 ]

And I

Answer 1

For generating such triangular matrices with such a regular pattern, use the toeplitz function, e.g.

m=toeplitz([1,0,0,0],[1,2,3,4])

for the other case, use rot90(m)