Removing empty cells from cell array

G is a cell array:

G={16x16 cell 16x16 cell 16x16 cell 16x16 cell 16x16 cell 16x16 cell}

Each cell look like this: G{1}=[1 [] 3 ; 4 [] 7]; (but 16x16)

I want to remove these empty cells []. I have tried

index = cellfun(@isempty, G) == 0;

Gnew = G(index)

Without success. How can I solve this?

[Stephen23]

"Each cell look like this: G{1}=[1 [] 3 ; 4 [] 7]; "

I doubt that, as numeric arrays must be rectangular and cannot contain "holes":

[1,[],3;4,[],7]

ans = 2×2

1 3 4 7

Please upload some sample data in a mat file by clicking on the paperclip button.

[Joel Schelander]

It is the output of several for loops, looks like this (see attached mat file)

Answer 1

[Stephen23]

Most likely converting the nested cell array to numeric arrays is going to make processing your data easier:

S = load('G.mat');
GUD = S.GUD

GUD = 1×6 cell array
    {16×16 cell}    {16×16 cell}    {16×16 cell}    {16×16 cell}    {16×16 cell}    {16×16 cell}

GUD{1}

ans = 16×16 cell array
    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {[  4.1165]}    {[  5.8874]}    {[  5.8474]}    {0×0 double}    {[  5.8874]}    {[  4.5514]}    {[  6.3844]}    {0×0 double}    {[  5.8474]}    {[  6.3844]}    {[  4.4562]}
    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {[  5.8874]}    {[  6.3844]}    {0×0 double}    {0×0 double}    {[  6.3844]}    {[  5.8474]}
    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {[  5.8874]}    {0×0 double}    {[  6.3844]}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {[  6.3844]}    {0×0 double}    {[  6.3844]}
    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {[  5.8474]}    {[  6.3844]}    {0×0 double}    {0×0 double}    {[  6.3844]}    {[  6.3844]}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}
    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {[  5.8874]}    {[  6.3844]}    {0×0 double}    {0×0 double}    {[  6.3844]}    {[  5.8474]}
    {[  4.1165]}    {0×0 double}    {[  5.8874]}    {[  5.8474]}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {[  5.8874]}    {0×0 double}    {[  4.2759]}    {[  5.8416]}    {[  5.8474]}    {0×0 double}    {[  5.8416]}    {[  4.3722]}
    {[  5.8874]}    {0×0 double}    {0×0 double}    {[  6.3844]}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {[  6.3844]}    {0×0 double}    {0×0 double}    {[  5.8416]}
    {[  5.8474]}    {0×0 double}    {[  6.3844]}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {[  6.3844]}    {0×0 double}    {[  5.8416]}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}
    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {[  5.8874]}    {0×0 double}    {[  6.3844]}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {[  6.3844]}    {0×0 double}    {[  6.3844]}
    {[  5.8874]}    {0×0 double}    {0×0 double}    {[  6.3844]}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {[  6.3844]}    {0×0 double}    {0×0 double}    {[  5.8416]}
    {[  4.5514]}    {[  5.8874]}    {0×0 double}    {[  6.3844]}    {[  5.8874]}    {[  4.2759]}    {0×0 double}    {[  5.8416]}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {[  6.3844]}    {[  5.8416]}    {0×0 double}    {[  4.7729]}
    {[  6.3844]}    {[  6.3844]}    {0×0 double}    {0×0 double}    {[  6.3844]}    {[  5.8416]}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}
    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {[  5.8474]}    {[  6.3844]}    {0×0 double}    {0×0 double}    {[  6.3844]}    {[  6.3844]}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}
    {[  5.8474]}    {0×0 double}    {[  6.3844]}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {[  6.3844]}    {0×0 double}    {[  5.8416]}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}
    {[  6.3844]}    {[  6.3844]}    {0×0 double}    {0×0 double}    {[  6.3844]}    {[  5.8416]}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}
    {[  4.4562]}    {[  5.8474]}    {[  6.3844]}    {0×0 double}    {[  5.8474]}    {[  4.3722]}    {[  5.8416]}    {0×0 double}    {[  6.3844]}    {[  5.8416]}    {[  4.7729]}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}    {0×0 double}

Convert:

for k = 1:numel(GUD)
    idx = ~cellfun(@isempty,GUD{k});
    tmp = zeros(size(GUD{k})); % or perhaps NAN.
    tmp(idx) = [GUD{k}{idx}];
    GUD{k} = tmp;
end

Checking:

GUD

GUD = 1×6 cell array
    {16×16 double}    {16×16 double}    {16×16 double}    {16×16 double}    {16×16 double}    {16×16 double}

GUD{1}

ans = 16×16

0 0 0 0 0 4.1165 5.8874 5.8474 0 5.8874 4.5514 6.3844 0 5.8474 6.3844 4.4562 0 0 0 0 0 0 0 0 0 0 5.8874 6.3844 0 0 6.3844 5.8474 0 0 0 0 0 5.8874 0 6.3844 0 0 0 0 0 6.3844 0 6.3844 0 0 0 0 0 5.8474 6.3844 0 0 6.3844 6.3844 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5.8874 6.3844 0 0 6.3844 5.8474 4.1165 0 5.8874 5.8474 0 0 0 0 5.8874 0 4.2759 5.8416 5.8474 0 5.8416 4.3722 5.8874 0 0 6.3844 0 0 0 0 0 0 0 0 6.3844 0 0 5.8416 5.8474 0 6.3844 0 0 0 0 0 6.3844 0 5.8416 0 0 0 0 0 0 0 0 0 0 5.8874 0 6.3844 0 0 0 0 0 6.3844 0 6.3844 5.8874 0 0 6.3844 0 0 0 0 0 0 0 0 6.3844 0 0 5.8416

If you really want to keep the (very inefficient and difficult to work with) nested cell arrays containing scalar numerics, then something like this:

for k = 1:numel(GUD)
    idx = ~cellfun(@isempty,GUD{k});
    GUD{k}(idx) = {0};
end

[Joel Schelander]

That really worked! Thank you!