Rearrange matrices in a cell array

Hello,

I am generating some 10 square matrices (4x4), say 1 to 10, using a for loop and storing it in a cell array. And I am also generating another square matrix (4x4), say x, which I would need to move to some position in the cell array depending on user input.

For example, if the user specifies 3, then the matrices should be rearranged such that,

1 then 2 then x then 3 then 4 and so on till 10.

Similarly, if the user specifies 2, then the arrangement would be,

1 then x then 2 then 3 and so on till 10.

It is very important that I reorder the matrix ‘x’ to the specified position, as I would be adding the matrix elements in each position in a particular way.

So how do I go about doing that?

I have written the following code so far,

n = 10 ;
gbsfm = cell(n, 1) ; 
for i = 1 : n 
a11 = rand(1,1)
a12 = rand(1,1)
a21 = rand(1,1)
a22 = rand(1,1)
A=[a11 a12 0 0; a21 a22 0 0; 0 0 0 0; 0 0 0 0]
gbsfm{i} = A
val = gbsfm{i};
gbsm = sprintf('matrix_%d.mat',i);
save(gbsm,'val');
end

But I have no idea as to how to proceed further. Any pointers would be very helpful.

Answer 1

[Alex Mcaulley]

data = cell(1,10);
data(:) = {deal(rand(4))};
idx = 1;
x = rand(4);

newData = [data(1:idx-1),x,data(idx:end-1)];

[vanrapa]

Thank you for simplying my code. Works perfectly. thank you.

Answer 2

[Daniel]

Hi vanrapa,

you would need to expand the existing cell array by one element, shift the existing elements and store the new matrix at the desired index...

Hope this helps...

% this would be the index you want your new matrix to be stored at
idx = 2;

% Expand the cell array by one element and shift the existing
% elements starting from idx
gbsfm(idx+1:end+1,1) = gbsfm(idx:end,1);

% insert the new matrix
gbsfm(idx,1) = newMatrix;

[vanrapa]

Thanks.

Sorry for the late reply. I generated a new 4 x 4 matrix and inserted it but I was getting the error, 'Conversion to cell from double is not possible'.

How do I resolve that?

[Daniel]

Sorry, you need to use curly braces in my last line of code...

% insert the new matrix
gbsfm{idx,1} = newMatrix;

[vanrapa]

I guessed so later and changed the last line,

gbsfm{1,idx} = newMatrix;

It generated desired results. Thanks.