MxM correlation Matrix output

Given a vector

Vec = [ 0 1 2 3 4 5 6 7 8 9 ]

I want to use the vec value to obtain a matrix output as

0 1 2 3 4 5 6 7 8 9

1 0 1 2 3 4 5 6 7 8

2 1 0 1 2 3 4 5 6 7

3 2 1 0 1 2 3 4 5 6

mat = 4 3 2 1 0 1 2 3 4 5

5 4 3 2 1 0 1 2 3 4

6 5 4 3 2 1 0 1 2 3

7 6 5 4 3 2 1 0 1 2

8 7 6 5 4 3 2 1 0 1

9 8 7 6 5 4 3 2 1 0

Your input is highly appreciated. Thanks in advance

Answer 1

[Andrei Bobrov]

toeplitz(vec)

[Evans Gyan]

Thank you Andrei. You really saved me the headache. It worked

Answer 2

[John D'Errico]

What does that even remotely have to do with a covariance matrix? :)

Now, IF your goal really is just to create that array, then try this:

vec = 0:9;
abs(vec - vec')
ans =
     0     1     2     3     4     5     6     7     8     9
     1     0     1     2     3     4     5     6     7     8
     2     1     0     1     2     3     4     5     6     7
     3     2     1     0     1     2     3     4     5     6
     4     3     2     1     0     1     2     3     4     5
     5     4     3     2     1     0     1     2     3     4
     6     5     4     3     2     1     0     1     2     3
     7     6     5     4     3     2     1     0     1     2
     8     7     6     5     4     3     2     1     0     1
     9     8     7     6     5     4     3     2     1     0

The above will work as long as you are using at least R2016b or MATLAB. Older releases will require tools like bsxfun, or even meshgrid.

It is a bit unclear because again, this has nothing to do with a covariance matrix, except that both are symmetric matrices.