how to find strings of varying length within longer strings

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I have a cell array where the first row of each column is a long string that always starts with "HA", then a number, and then more text.
For example:
HA2.hdhashasdh HA33.dskljdasjkdajkls HA80.djklasjdjklads HA81.djkhadsh HA245.fsaldjajdalsj
Then I have a vector with some of the numbers that come after 'HA'
list = [2, 81, 245]
I want to make a loop that for each string of my cell array, finds whether it starts with 'HA[one of the numbers in my list]', and returns 1 if it does and 0 if it doesn't.
I've tried to use strncmp, but there were some problems.
This is the loop I was using:
counter = 1
for i=1:length(myArray(1, :))
question = myArray(1, i); %the string I'm currently looking at
num = list(counter); %the question number
name = strcat('HA', num2str(num)); %the name of the question (e.g. HA42)
if strncmp(name, question, 4) == 1
question
name
counter = counter +1;
end
end
The problem is that 'name' is not always the same length, since the numbers in my list are 2, 80 and 245. So if I do strncmp(name, question, 4) or strncmp(name, question, 5), it always returns 0, but if I do strncmp(name, question, 3) it can return 1 even though it's wrong: for example if name is HA81, it will return 1 once it's on question HA80.jdfdskljf.
I wanted to know if there is another function to do this or any way I could make it work. Let me know if anything wasn't clear (I'm still newish to Matlab) Thanks!

Accepted Answer

Azzi Abdelmalek
Azzi Abdelmalek on 8 Jul 2015
Edited: Azzi Abdelmalek on 8 Jul 2015
str={'HA2.hdhashasdh'   'HA33.dskljdasjkdajkls'  'hh'  'HA80.djklasjdjklads'  'HA81.djkhadsh'  'HA245.fsaldjajdalsj' 'er'}
list=[2,81,245]
n=regexp(str,'(?<=HA)\d+\>','match','once')
id=str2double(n)
out=ismember(id,list)

More Answers (1)

Alex
Alex on 8 Jul 2015
Try strfind.
  1 Comment
NB
NB on 9 Jul 2015
strfind doesn't do what I want it to do: I want something that like strcmp gives me a 1 if it finds the string and a 0 if it doesn't. It seems like there should be a way to use strncmp (which compares not the entire string but just a certain number of characters) but with varying numbers of characters (e.g. from 3 to 5 characters). Or do you think maybe there is a way to use strfind to do this?

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