MATLAB: Using regexp with negative and positive floating numbers

cell arrays

data = 
      '0.00640869<'
      '0.00640869<'
      '-0.00598145'
      '-0.00598145'
      '-0.0010376<'
      '-0.0010376<'
      '-0.00604248'
      '-0.00213623'
      '0.00567627<'
      '-0.00219727'
      '0.00567627<'
% 11x1 cell
to remove the non-numeric character;
data_num = regexp(data,'[0-9]+.[0-9]+', 'match');
In this case, negative signs (-) are also removed. How can I modify this code to get – signs?

Best Answer

regexp(data,'[+-]?\d+\.?\d*', 'match');
Notes:
  1. important: . does NOT match the period character, but in fact it matches any character. To only match the period, you need to escape it: \.
  2. \d matches any digit, and is simpler than writing [0-9]
  3. by making the decimal fraction optional my answer will also match integer values
Read the MATLAB documentation for more information:
https://www.mathworks.com/help/matlab/matlab_prog/regular-expressions.html
You might also like to try my FEX submission, which lets you experiment with regular expressions and see their output in real time (as you type):
https://www.mathworks.com/matlabcentral/fileexchange/48930-interactive-regular-expression-maker
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