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Looking for an alternative to regexp.

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Bob Thompson
Bob Thompson on 23 Mar 2021
Edited: Stephen Cobeldick on 25 Mar 2021
I'm looking for an alternative way to parse through strings to find bits of information, or for a way to use regexp that doesn't give me nested cells. I'm tired of dealing with the nested cells.
I've got a string that contains node numbers and locations. I would like to capture all of the node numbers, and then put them into a double array. I can identify and extract the numbers with regexp, but any time I use regexp with tokens I end up with cells inside of cells for a reason that I don't entirely understand. Am I doing something to create the extra layer of cells, or is there another command that can parse and extract the information I want?
singlestring = 'nxyzs=74xyz[0]:-2.0447000e+010.0000000e+001.8288000e+00Nearestnodeis7736664atadistanceof4.6823094e-03locatedat-2.0451682e+012.2396341e-161.8288000e+00';
repeatstrings = repmat(singlestring,1,5);
nodes = regexp(repeatstrings,'Nearestnodeis(\d+)','tokens');
The nodes variable will contain a 1x5 cell matrix, where each cell contains a 1x1 cell, which contains the node number string.
  2 Comments
Bob Thompson
Bob Thompson on 24 Mar 2021
Thanks, I definitely think this is more smooth than what I usually attempt.

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Answers (2)

Star Strider
Star Strider on 23 Mar 2021
See if adding either:
Out = cell2mat([nodes{:}].')
or:
Out = str2num(cell2mat([nodes{:}].'))
to the posted code provides the desired result.
Note that str2num is not generally recommended, however it works when str2double produces an unacceptable result.

Walter Roberson
Walter Roberson on 23 Mar 2021
singlestring = 'nxyzs=74xyz[0]:-2.0447000e+010.0000000e+001.8288000e+00Nearestnodeis7736664atadistanceof4.6823094e-03locatedat-2.0451682e+012.2396341e-161.8288000e+00';
repeatstrings = repmat(singlestring,1,5);
nodes = regexp(repeatstrings,'Nearestnodeis(?<NN>\d+)','names');
str2double({nodes.NN})
ans = 1×5
7736664 7736664 7736664 7736664 7736664
  3 Comments
Bob Thompson
Bob Thompson on 24 Mar 2021
Thanks for the explanation. I do like structures better than cells, most of the time.

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