CODEWITHSUNDEEP
matlabcells
Gloria
Gloria

Reputation: 329

remove rows that contain zeros from cells array in matlab

I have a cell array resulted from a certain code as follows:

m = 

    [         0]    'GO:0008150'
    'GO:0008150'    'GO:0016740'
    'GO:0016740'    'GO:0016787'
    'GO:0016787'    'GO:0006810'
    'GO:0008150'    'GO:0006412'
    'GO:0016740'    'GO:0004672'
    'GO:0016740'    'GO:0016779'
    'GO:0016787'    'GO:0004386'
    'GO:0016787'    'GO:0003774'
    'GO:0016787'    'GO:0016298'
    'GO:0006810'    'GO:0016192'
    'GO:0006412'    'GO:0005215'
    'GO:0004672'    'GO:0030533'
    [         0]    'GO:0008150'
    [         0]    'GO:0016740'
    'GO:0008150'    'GO:0016787'
    'GO:0008150'    'GO:0006810'
    'GO:0006810'    'GO:0006412'
    [         0]    'GO:0004672'
    [         0]    'GO:0016779'
    [         0]    'GO:0004386'
    'GO:0016192'    'GO:0003774'
    [         0]    'GO:0016298'
    [         0]    'GO:0016192'
    'GO:0006810'    'GO:0005215'
    'GO:0005215'    'GO:0030533'

I need to remove the rows which contains zero (for example: row one should be deleted because we have a zero in the first column). so how can I create an array from this array that doesn't contain zeros?

Upvotes: 4

Views: 2748

Answers (2)

Rody Oldenhuis
Rody Oldenhuis

Reputation: 38032

You can do this in a pretty one-liner:

m(any(cellfun(@(x)x(1)==0, m),2), :) = []

Alternatively: 

m(any(~cellfun(@ischar, m),2), :) = []

which is a tad faster.

If you can be certain that only the first column will ever contain a zero, use

m = m(cellfun(@ischar, m(:,1)),:)

and, finally, you can use

m = m(cellfun('isclass', m(:,1), 'char'),:)

which looks "old", but actually has greater performance.

Testing these one thousand times on your example array, gives

Elapsed time is 1.382801 seconds.
Elapsed time is 0.138519 seconds.
Elapsed time is 0.075245 seconds.
Elapsed time is 0.014674 seconds.

Upvotes: 6

Andrey Rubshtein
Andrey Rubshtein

Reputation: 20915

  zerosLocation = cellfun(@(x)isEqual(x, 0 ) , m);
  zeroRows = any(zerosLocation,2);
  m(zeroRows,:) = [];

Upvotes: 2

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