MATLAB: Updating/inserting summary array

updating/inserting summary array

hi, i have a summary array where it keeps a count of repeated items. e.g
sumarray = {'red',  2; ...
      'blue', 3}
etc. While running a for loop, if a red item appears, I simply want to increment the count to 3 for 'red', if a new category comes in e.g. 'pink' I simply want to add a new row {'pink',1}. What is the most efficient way to implement this?
Thanks.

Best Answer

You can use ismember() to check if it's in the list. If it is, increment the second column, if it's not, append it on to the end with a count of 1. See demo code below:
sumarray = {'red',  2; ...
      'blue', 3}
    
% Pick one or the other (red or pink) to test the code.
testWord = 'red'
testWord = 'pink'
column1 = sumarray{:,1}
rowIndex = ismember(testWord, column1, 'rows')
if rowIndex >= 1
  sumarray{rowIndex,2} = sumarray{rowIndex, 2} + 1;
else
  % Not in there yet.  Add it to the end
  sumarray{end+1,1} = testWord;
  sumarray{end,2} = 1;
end
% See what we ended up with
sumarray
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