How to create a diagonal matrix that starts at (1,1)?

Can someone help me?

How do I create a diagonal matrix of lambda, where lambda = 0.2? I would like the diagonal to start at (1,1).

Any help would be greatly appreciated.

[Renea Young]

i know it is something like

lambda = 0.2;

x = diag(lambda, (1,1));

However, it's not correct.

[Jan]

What is the wanted output? Which dimension should the output have?

[Renea Young]

The output should be A = [0 0 0 0 0 ....0;0 0.200 0 0 0 .....0;0 0 0.200 0 0...0; 0 0 0 0.200 0 ....0]

The dimension is N

Answer 1

[Star Strider]

Without using repmat —

n = 4;
lambda = 0.2;
A = diag([0 ones(1,n)]*lambda)

A = 5×5

0 0 0 0 0 0 0.2000 0 0 0 0 0 0.2000 0 0 0 0 0 0.2000 0 0 0 0 0 0.2000

,

Answer 2

[Jan]

Maybe you mean:

n = 4;
lambda = 0.2;
A = eye(n) * lambda

A = 4×4

0.2000 0 0 0 0 0.2000 0 0 0 0 0.2000 0 0 0 0 0.2000

% Or:
A = diag(repmat(lambda, 1, n))

A = 4×4

0.2000 0 0 0 0 0.2000 0 0 0 0 0.2000 0 0 0 0 0.2000

Answer 3

[Walter Roberson]

n = 4;
lambda = 0.2;
A = diag(repmat(lambda, 1, n), 1)

A = 5×5

0 0.2000 0 0 0 0 0 0.2000 0 0 0 0 0 0.2000 0 0 0 0 0 0.2000 0 0 0 0 0