Matrix dimensions to create for loop?

Hi all. I have rr(6x200) matrix. I want to find Rc and V matrixes for each 200 column, I showed below for one column:

    Rc=toeplitz(rr(1:6));    %Rc(6x6)

    V=Rc\eye(6,1);           %V(6x1)

In the end, I need V matrix (6x200) but because of Rc is (6x6) matrix I could not create for loop.

[Jos (10584)]

You meant R= toeplitz(rr(:,k)), where k runs from 1 to 200?

Answer 1

[Guillaume]

I'm not sure why you can't use a loop:

V = zeros(size(rr));
denum = eye(size(rr, 1), 1); %so it's not recreated 200 times in the loop
for col = 1 : size(rr, 2)
   Rc = toeplitz(rr(:, col));
   V(:, col) = Rc \ denum;
end

Alternatively:

denum = eye(size(rr, 1), 1);
V = cell2mat(cellfun(@(col) toeplitz(col)\denum, num2cell(rr, 1), 'UniformOutput', false))

The loop is likely to be marginally faster.

Answer 2

[Jos (10584)]

You can use a for-loop:

rr = rand(6,200) ;
[nr,nc] = size(rr) ;

X = eye(nr,1) ; % take it out of the loop 
V = zeros(nr,nc) ; % pre-allocation
for k=1:nc  % loop over columns
   Rc = toeplitz(rr(:,k)) ;
   V(:,k) = Rc \ X ;
end

Answer 3

[jack star]

Both works fine, thanks a lot.