Using cellfun and regexp question

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m j
m j 2020-7-30
评论： the cyclist 2020-7-31
Hello,
I have a cell called storedSamplerates = 1X9;
Each cell has a string ex:
storedSamplerates{1} = 'SAMPLERATE: 50000'
storedSamplerates{2} = 'samplerate:200000'
etc.....
I am trying to remove the 'SAMPLERATE:' and 'samplerate:' portion of the cells regardless of case, so only the number is left. I can successfully use regexp with 'ignorecase', to remove this in a loop with:
sampleRates = regexp(storedSamplerates{i},'(\d+)','match','ignorecase');
So that im only left with numbers.
sampleRates{1} = '50000';
sampleRates{2} = '200000'
etc....
But I wanted to try using cellfun to have simpler code and have failed:
sampleRates(cellfun(@(x) regexp(x ,'(\d+)','match','ignorecase'),storedSamplerates));
Using cellfun and regexp seems possible,I just dont know where im messing up?
  1 个评论
Stephen23
Stephen23 2020-7-31
编辑：Stephen23 2020-7-31
Note that because your regular expression does not match any alphabetic characters (it only matches digits) the 'ignorecase' option is completely superfluous. It does nothing, zilch, nada, zero. Get rid of it.
Also the grouping parentheses do nothing. Get rid of them.

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采纳的回答

the cyclist
the cyclist 2020-7-31
编辑：the cyclist 2020-7-31
I think this does what you want.
storedSamplerates{1} = 'SAMPLERATE: 50000';
storedSamplerates{2} = 'samplerate:200000';
cellfun(@(str)regexp(str,'\d*','match'),storedSamplerates)
  2 个评论
m j
m j 2020-7-31
Hey,
Thanks,this does exactly what I wanted!
Stephen23
Stephen23 2020-7-31
编辑：Stephen23 2020-7-31
@m j: you picked the slower, more complex solution (1e4 iterations):
Elapsed time is 2.519055 seconds. % this complex answer
Elapsed time is 0.127693 seconds. % my simple answer

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更多回答（1 个）

Stephen23
Stephen23 2020-7-31
编辑：Stephen23 2020-7-31
The simple and efficient solution is to use the 'once' option:
sampleRates = regexp(storedSamplerates,'\d+','match','once');
% ^^^^^^^^^^^^^^^^^ entire array, no indexing!
Wrapping regexp in cellfun does much the same thing, just slower and more complex.
  2 个评论
the cyclist
the cyclist 2020-7-31
Yes, should definitely swap to this accepting this one! The cellfun is a needless complication in my solution.

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