Using cellfun and regexp question

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m j
m j el 30 de Jul. de 2020
Comentada: the cyclist el 31 de Jul. de 2020
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 comentario
Stephen23
Stephen23 el 31 de Jul. de 2020
Editada: Stephen23 el 31 de Jul. de 2020
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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Respuesta aceptada

the cyclist
the cyclist el 31 de Jul. de 2020
Editada: the cyclist el 31 de Jul. de 2020
I think this does what you want.
storedSamplerates{1} = 'SAMPLERATE: 50000';
storedSamplerates{2} = 'samplerate:200000';
cellfun(@(str)regexp(str,'\d*','match'),storedSamplerates)
  2 comentarios
m j
m j el 31 de Jul. de 2020
Hey,
Thanks,this does exactly what I wanted!
Stephen23
Stephen23 el 31 de Jul. de 2020
Editada: Stephen23 el 31 de Jul. de 2020
@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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Más respuestas (1)

Stephen23
Stephen23 el 31 de Jul. de 2020
Editada: Stephen23 el 31 de Jul. de 2020
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 comentarios
Walter Roberson
Walter Roberson el 31 de Jul. de 2020
This is what I would use.
the cyclist
the cyclist el 31 de Jul. de 2020
Yes, should definitely swap to this accepting this one! The cellfun is a needless complication in my solution.

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