Build determinantes of matrices in cell arrays

I have a cell array X with dimension (N x 2) and N is an even number. This cell array is filled with (2 x 2) Matrices of type double.

I'm wondering, if there is a way to build the determinants of each of those matrices (type: double) in a vectorized manner without using a for loop.

My solution was:

   Y = zeros(N,1)
for i = 1:N
   Y = det(X{i});
end

Now I have this Y of size (N x 1), which will contain all the determinants of the (2 x 2) matrices stored in the cell array X with size (N x 2).

Can I "vectorize" the for loop in some way or the other?

Thanks for having a look at this!

Answer 1

[KSSV]

doc cellfun

N = 4 ;
X = cell(N,2) ;
for i = 1:N
    X{i,1} = rand(2) ;
    X{i,2} = rand(2) ;
end
detX = cellfun(@det,X) ;

[Ahmed Hossam]

I have just looked here:

https://ch.mathworks.com/help/matlab/ref/cellfun.html

I think, that I can do that in one line with the help of cellfun!?!

[Ahmed Hossam]

Thanks!

[Ahmed Hossam]

If I would like to build the inverse of symmetric matrices stored in the cells, could I also use the same function and call the @inv function? Is there a more effective way also available in matlab?!

[Stephen23]

@Ahmed Hossam: it is seldom required to calculate a matrix inverse. If you are solving systems of equations, then MATLAB has much better methods available. Read the inv help carefully to know what the "more effective" methods are.

[Jan]

While the cellfun method is nice, it is not "vectorized" actually. You only do not see the loop anymore. Internally you cannot treat the cell elements in a vectorized way.