MATLAB: Indexing a cell, ignoring empty inputs

cell arrayindexingMATLAB

I have a cell that looks like this:
    'GS_L'     'OECF'          'DYNAMIC_RANGE'
    'GS_R'     'OECF'          'DYNAMIC_RANGE'
    'GS_U'     'OECF'          'DYNAMIC_RANGE'
    'GS_D'     'OECF'          'DYNAMIC_RANGE'
    'HOR_B'    'UNIFORMITY'    '0'            
    'HOR_W'    'UNIFORMITY'    '0'            
    'HOR_G'    'UNIFORMITY'    '0'            
    'VER_B'    'UNIFORMITY'    '0'            
    'VER_W'    'UNIFORMITY'    '0'            
    'VER_G'    'UNIFORMITY'    '0'
I want to take the first row of the cell that have the word OECF in it.
So I apply this:
     OECFINDEX = strfind(measureables,'OECF');
Which gives:
    []    [1]    []
    []    [1]    []
    []    [1]    []
    []    [1]    []
    []     []    []
    []     []    []
    []     []    []
    []     []    []
    []     []    []
    []     []    []
Now I do this:
    OECFMES = measureables(find([OECFINDEX{:}] == 1)',1);
Which gives me:
    'GS_L'
    'GS_R'
    'GS_U'
    'GS_D'
Now, this seems to be working but when I try it for UNIFORMITY,
     UNIFORMITYMES = measureables(find([UNIFORMITYINDEX{:}] == 1)',1);
It shows:
    'GS_L'
    'GS_R'
    'GS_U'
    'GS_D'
    'HOR_B'
    'HOR_W'
Instead of
    'HOR_B'               
    'HOR_W'               
    'HOR_G'            
    'VER_B'              
    'VER_W'            
    'VER_G'
Does it ignore empty cell inputs? Or what is going on, and is there a way to fix this?
Kind regards,
Thomas Koelen

Best Answer

Hi Thomas,
yes it does. Do you really look for OECF in each string, or do you want to compare to OECF? For your example at least, the following works better:
UNIFORMITYINDEX = strcmp(measureables(:,2), 'UNIFORMITY')
measureables(UNIFORMITYINDEX, 1)
ans = 
  'HOR_B'
  'HOR_W'
  'HOR_G'
  'VER_B'
  'VER_W'
  'VER_G'
Note, that I used strcmp instead of strfind. Don't know if that fit's only this example, though...
If strmatch is indeed the right function, use cellfun:
measureables(~cellfun(@isempty, UNIFORMITYINDEX(:,2)), 1)
Titus
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