MATLAB: Matrix of circulating vectors without loop

Question

hi all , I want to built a matrix of circulating vectors without using loops

 for example

input:

     1     2     3     4
     4     5     6     7
     3     8     4     6

output :

     1     2     3     4
     4     1     2     3
     3     4     1     2
     2     3     4     1
     4     5     6     7
     7     4     5     6
     6     7     4     5
     5     6     7     4
     3     8     4     6
     6     3     8     4
     4     6     3     8
     8     4     6     3

I use the code

v =[1,2,3,4;4,5,6,7;3,8,4,6]
%notice the length of each vector in v is equal 
len_rows=length(v(:,1)); 
   len_cols=length(v(1,:)); 
   mat_shifted=zeros(len_rows*len_cols,len_cols);
   j=1;
   for i=1:len_rows
       vec=v(i,:);
mat=toeplitz([vec(1) fliplr(vec(2:end))], vec)
mat_shifted(j:j+len_cols-1,:)=mat
j=j+len_cols;
   end

is there a smart way to do it without using loops , thanks in advance

Answer 1

Not necessarily better in performance, but if you really want to avoid explicitly calling a loop, try

y = arrayfun(@(r)gallery('circul',x(r,:)),1:size(x,1),'UniformOutput',false);
cat(1,y{:})

HTH