MATLAB: Is there a method to extract all the data from a nested cell array when each nested cell is of a different size

nested cell arrays

For example
1x1 cell  
1x2 cell
1x19 cell
1x20 cell

This will produce a ragged array but is there a work around

Best Answer

Hi George,

My first thought would be to apply a recursive function using the cellfun . e.g.

function C =extractmycells(C)
if iscell(C)
    C = cellfun(@extractmycells, C, 'UniformOutput', 0);
    C = cat(2,C{:});
else
    C = {C};
end
end

As an example

>> B = {1,{2},{3,4,5},{6,7,8,9}}
B = 
      [1]    {1x1 cell}    {1x3 cell}    {1x4 cell}
>> C =extractmycells(B)
C = 
      [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]

Regards,

Related Solutions

MATLAB: Nested structure

fn = fieldnames(info.ROIcontour1);
fn = fn(strncmp(fn,'Slice',5));
nf = length(fn);
contourslices = cell(nf,1);
for K = 1 : nf
  countourslices{K} = info.ROIcontour1.(fn{K}).contourdata;
end

MATLAB: Nest loop

Why do you think all aren't being calculated? Here is a modified version of your code, not changing the mechanics, which shows what you are getting.

a = 1:3;
b = 1:3;
for i = 1:3;
    for j = 1:3;
        a_pred = a(:,i);
        b_pred = b(:,j);
        disp([a_pred b_pred])    
    end  
end

EDIT

Here is how to store all the results in chi2:

x = 1:3;
y = 1:3;
a = 1:3;
b = 1:3;
chi2 = zeros(9,3);
cnt = 0;
for i = 1:3;
    for j = 1:3;
        cnt = cnt + 1;
        a_pred = a(:,i);
        b_pred = b(:,j);
        y_pred = a_pred + b_pred.* x
        chi2(cnt,:) = (y-y_pred).^2;
    end  
end
chi2

And here is a vectorized version, using NPERMUTEK:

IDX = npermutek(1:3,2);
y_pred = bsxfun(@plus,a(IDX(:,1)), bsxfun(@times,b(IDX(:,2)),x.'));
chi2 = bsxfun(@minus,y,y_pred.').^2

Not that it should be faster here...

Best Answer

Related Solutions

MATLAB: Nested structure

MATLAB: Nest loop

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