Effective matrix defining (diagonals)

hi, i would like to get some help with defining the next matrix in the easiest way. i know the diag() function but i didnt find a way the define the non-main diagonals.

Answer 1

[Stephen23]

N = 7;
M = toeplitz([-2,1,zeros(1,N-2)])

M = 7×7

-2 1 0 0 0 0 0 1 -2 1 0 0 0 0 0 1 -2 1 0 0 0 0 0 1 -2 1 0 0 0 0 0 1 -2 1 0 0 0 0 0 1 -2 1 0 0 0 0 0 1 -2

[Nitzan Haviv]

thanks a lot!

[Stephen23]

@Nitzan Haviv: my pleasure! Remember to click the accept button if my answer helped you!

Answer 2

[Nitzan Haviv]

btw i found another way

when N is the dimention of the square matrix

d_sec = ones(1,N-1);
d_main= ones(1,N).*-2;
H = diag(d_main)+diag(d_sec,-1) + diag(d_sec,1);