how to generate matrix with any size in same pattern

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

i need to generate a matrix with pattern like this. how to write a script that the required pattern

for example, if i need 5*5 matrix with the required pattern it will be like this

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

or i need 7*7 matrix

 -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

[per isakson]

Homework?

Answer 1

[Walter Roberson]

See http://www.mathworks.com/help/matlab/ref/diag.html

Answer 2

[Andrei Bobrov]

n = 5;
out = full(spdiags(ones(n,1)*[1 -2 1],-1:1,n,n));

or

out = zeros(n);
out([2:n+1:end,n+1:n+1:end]) = 1;
out(1:n+1:end) = -2;

or

out = zeros(n);
z = diag(true(n-1,1),-1);
out(z | z') = 1;
out(eye(n) > 0) = -2;

and (after 6.5 years ;)

n = 10;
out = toeplitz([-2 1 zeros(1,n-2)]);

Answer 3

[Bandar]

n=5;
v =-2*ones(1,n);
p =ones(1,n-1);
B =diag(v);
C =diag(p,1);
D =diag(p,-1);
A=B+C+D

The result is

A =

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