Searching for a string in a very efficient way
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Hi.
I have two cell arrays, A and B. A contains 3000 strings and B contains 107,000 strings. Some of the strings in B might also be present in A. Each of these strings is a 7 letter word. I need to find which strings in B are also present in A. I did this by writing the following:
[~,p] = ismember(A, B);
p(p==0) = []; % removing zeros from the p array
I then use the indices in p to get the strings in B that are also in A. This works but takes a long time to compute (0.4 sec). Since I need to do this step about 30 times (for other A and B), the overall time becomes large. Does anyone have an idea of how to make this string search faster. With thanks in advance, G
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Accepted Answer
Azzi Abdelmalek
on 17 Jul 2013
Edited: Azzi Abdelmalek
on 17 Jul 2013
Instead of ismember(B, A), You should use
ismember(A,B);
More Answers (1)
Jan
on 17 Jul 2013
ismember sorts the input strings to allow for an efficient binary search. If you call this 30 times, sorting the larger cell string explicitly will save 29 sorting procedures.
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