Matlab - vectorized way to indices in cell array equal string

Question

I have a 435x1 cell array whose elements are either 'y', 'n', or '?'. I want to find which indices are equal to 'y'.

With normal arrays, I just use the find function. But I can't use that with cell arrays because eq is not defined for type cell.

I think I can go through each element and do

for index=1:size(cell_array,1)
    if cell_array{index} == 'y'
        %add index to some array of indices
    end
end

But is there a vectorized way to go through the array and find indices contain elements that are equal to 'y'? Any help is appreciated.

possible duplicate of [How to search for a string in cell array in MATLAB?](http://stackoverflow.com/questions/8061344/how-to-search-for-a-string-in-cell-array-in-matlab) — Eitan T, Oct 29 '13 at 07:00
@EitanT - I think Sterling was most interested in the `[cell_array{:}]=='y'` bit, which was not a possible solution for the other question, so `find` could be used in the familiar way with `eq`. It's much the same functionally, I'll admit. — chappjc, Oct 29 '13 at 07:11

chappjc · Answer 1 · 2013-10-29T04:32:21.817

5

Since you know each cell will contain a single character you can concatenate all the cell elements and do a single vectorized test:

find([cell_array{:}]=='y')

Possibly the most straightforward way is just to use strcmp, which can accept a cell array as the second argument:

find(strcmp('y',cell_array))

edited Oct 29 '13 at 04:32

answered Oct 29 '13 at 03:31

chappjc

1

More precisely, you'd want `find(strcmp('y',cell_array))`, so that you'd get the indices of the 'y' values. – MrAzzaman Oct 29 '13 at 04:28
Thanks, I'll clarify that you need `find` around `strcmp`. – chappjc Oct 29 '13 at 04:32
+1 The second method is more general, as it doesn't require single-chracter strings – Luis Mendo Oct 29 '13 at 11:20

1 Answers1