Hi everyone ! can anyone help me to do this , thank you

Asked by mina massoud

mina massoud (view profile)

on 14 May 2019
Latest activity Commented on by mina massoud

on 14 May 2019

madhan ravi (view profile)

% I'd like to take the first 4x4 block of X and put it in Xa and Xb
% in such a way as to take the first and second column of X and put it in the first and second column in Xa
% and take the third column and the fourth column of X and put it in the third and fourth column of Xb
% second block 4x4 of X
% the (5,6) column of X in the (5,6) column of Xa
% the (7,8) column of X in the (5,6) column of Xb
clear all
clc
P=2;
M=4;
X=rand(M,P*M);
Xa=zeros(M,P*M);
Xb=zeros(M,P*M);

Fangjun Jiang

Fangjun Jiang (view profile)

on 14 May 2019
double check all the column numbers in your question and make sure they are correct.
mina massoud

mina massoud (view profile)

on 14 May 2019
yes you are wright becasue at the end i need to make somthing like this for P=4:-
Xa(:,1:2)= X(:,1:2)
Xb(:,3:4)= X(:,3:4)
Xa(:,5:6)= X(:,5:6)
Xb(:,7:8)= X(:,7:8)
Xa(:,9:10)= X(:,9:10)
Xb(:,11:12)= X(:,11:12)
Xa(:,13:14)= X(:,13:14)
Xb(:,15:16)= X(:,15:16)
so can i do it with somthing more general , thank u

R2019a

madhan ravi (view profile)

on 14 May 2019
Edited by madhan ravi

madhan ravi (view profile)

on 14 May 2019

[~,n]=size(X);
xai=[1:4:n,2:4:n];
xbi=[3:4:n,4:4:n];
Xa(:,xai)=X(:,xai)
Xb(:,xbi)=X(:,xbi)

Fangjun Jiang

Fangjun Jiang (view profile)

on 14 May 2019
this would be my guess. n=size(X,2), sort() is not needed.