How to create an n by n wilkinson matrix using diag

How to create an n by n wilkinson bidiagonal matrix

[Walter Roberson]

Do you mean a matrix such as https://www.mathworks.com/help/matlab/ref/wilkinson.html ?

[Colani Dlamini]

Yes, but the bidiagonal form not the tridiagonal form of wilkinson matrix.

[Guillaume]

I know nothing about wilkinson matrices but every reference I find only mention tridiagonal matrices.

[Walter Roberson]

It looks like for the bidiagonal form, that the main diagonal should be n:-1:1 and that the diagonal to the right of it should be all n .

You can construct bidiagonal matrices by using diag() to construct each of the diagonals, and adding the matrices together.

[Alejandra Lizarazo]

I have the same problem, could you solve that?

Answer 1

[Bruno Luong]

n = 10;
W = spdiags([n:-1:1; n*ones(1,n)]',[0 1],n,n);

[Walter Roberson]

I believe that this is a homework assignment that specifically requires diag() be used.