How can I extract the upper triangular part of a matrix and set only the off-diagonal values to pi?

Hi all,

I got a matrix A = ones(1,1).

When I use triu(ones(1,1)) the lower triangular part of the matrix gets zero.

What I need to do is that instead of zero it gets pi.

That means: 1 1 1 pi 1 1 pi pi 1

Is there any possibility to integrate this into the triu function?

Thanks!

Answer 1

[Jos (10584)]

Your statements make no sense: ones(1,1) wil give you the scalar 1 ...

I think you are after something like this:

N = 3
A = ones(N)
tf = tril(true(N),-1)
A(tf) = 2

Answer 2

[Andrei Bobrov]

out = pi*tril(A,-1) + triu(A)