Shifting columns in matrix Matlab

Dear members,

I have a matrix in which its tril and triu are zeros

And I want to shift up its rows

How can I program it in Matlab please?

[Walter Roberson]

Probably adding transposed tril and triu

[the cyclist]

What is in the matrix locations that are "empty" in your top image of H. (An element of a numeric array cannot be empty.)

Can you upload the matrix H in a MAT file?

[Afluo Raoual]

@the cyclist The empty elements are replaced all by zero elements

Answer 1

[the cyclist]

Slightly simpler version of @Nora Khaled's idea. It will also generalize to an (N-1) X N array in a way that I believe makes sense, in case that is important.

[~,c] = size(H);
r = c/2;

M = zeros(r,c);

for i=2:2:c
    j = i/2;
    M(:,i-1:i) = H(j:j+r-1,i-1:i);
end

You don't really need to define r or j as a separate variable, but I think it is a bit clearer.

Also, if you did need this for large arrays, it is more memory-efficient to preallocate M as I did, rather than building it by continually appending.

[Afluo Raoual]

Thank you so much. It works

Answer 2

[Nora Khaled]

clear all; 
clc

H=[0 0 0 0 0 0 0 0 0 0
   0 1 1 1 0 0 0 0 0 0
   1 1 1 0 0 1 0 0 0 0
   1 0 0 1 1 0 0 1 0 0
   1 1 0 0 1 1 1 0 0 1
   0 0 1 1 1 0 1 1 1 0
   0 0 0 0 0 1 0 0 1 1
   0 0 0 0 0 0 1 1 0 0
   0 0 0 0 0 0 0 0 1 1];
[~,c]=size(H);
j=0;
M=[];
for i=1:2:c
    j=j+1;
    M=[M H(j:j+4,i:i+1)];
end

[Afluo Raoual]

Thank you so much. It works