MATLAB: How to use findpeaks for every column of a matrix and store the result in a cell array

Question

I am trying to run this code:

for i=1:numel(locs1)
  peak_1q{i}=findpeaks(Qxy(:,numel(locs1)));
end;

I am getting this error:

Cell contents assignment to a non-cell array object.
Error in T_5Dec4 (line 52)  
peak_1q{i}=findpeaks(Qxy(:,numel(locs1)))

I need to store the value in a cell array,each column may have more than 1 peak .If I store it in a matrix (preallocated before the for loop,I get only the peaks for the last iteration of the loop. if I use

   peak_1q(i)=findpeaks(Qxy(:,numel(locs1)))

I get this error:

    In an assignment  A(:) = B, the number of elements in A and B must be the same.
Error in T_5Dec4 (line 53)
  peak_1q(i)=findpeaks(Qxy(:,numel(locs1)))

Any suggestions? How do I find and store the peaks from each column of the given data?

Answer 1

Preallocate it as a cell array:

peak_1q = cell(1,numel(locs1));

If you do not preallocate then apparently you have some already-existing non-cell variable in the workspace, and MATLAB will try to use that.

https://www.mathworks.com/help/matlab/matlab_prog/preallocate-memory-for-a-cell-array.html