MATLAB: Need to remove ‘~’ in column 5 of text file

text file

content = fileread('mwithin21rm.txt');
linestocopy = regexp(content, '^([^|]*\|){5}~\|.*$', 'match', 'dotexceptnewline', 'lineanchors');
newfile = fopen('m21rmmorphU.txt', 'wt');
fprintf(newfile, strjoin(linestocopy, '\n'));
fclose(newfile);
I need to remove the '~' in column 4 from each line of the text file. The code above moves those lines into a new text file, but I need to eliminate those lines instead. I have attached the file, mwithin21rm.txt.

Best Answer

UPDATE 5:04pm
 % - Read original.

 content = fileread( 'mwithin21rm.txt' ) ;
 % - Match and eliminate lines without pattern matching.
 sepId = reshape( strfind( content, '|' ), 18, [] ) ;
 match = content(sepId(4,:)+1) == '~' ;
 lines = strsplit( content, '\n' ) ;
 lines(match) = [] ;
 % - Export updated content.

 fId = fopen( 'm21rmmorphU.txt', 'w' ) ;
 fprintf( fId, strjoin( lines, '\n' )) ;
 fclose( fId ) ;
FORMER
If I understand well (in particular about col. 5), you want something like this:
 % - Read original.
 content = fileread( 'mwithin21rm.txt' ) ;
 % - Replacement which avoids pattern matching.
 sepId  = reshape( strfind( content, '|' ), 18, [] ) ;
 match  = content(sepId(4,:)+1) == '~' ;
 content(sepId(4,match)+1) = '' ;
 % - Export updated content.
 fId = fopen( 'm21rmmorphU.txt', 'w' ) ;
 fwrite( fId, content ) ;
 fclose( fId ) ;
PS: I love regular expressions ;-) but this seems to be a case where we can avoid their complexity.
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