MATLAB: How to read text files using regular expressions

regular expressiontextscan

What is a fast way to read lines that matches some regular expressions from a text file? For example, read only the lines starting with integer, and split this line by spaces into a vector. I would like to use textscan, because it is very fast.

An example file looks like this:

Best Answer

textscan is not able process regular expressions.

You can read the entire file in at one time using fileread, into a string. You can use regexp or regexprep to select portions of the string, for which you will probably need to use the options 'lineanchors' and 'dotexceptnewline'. You can then enter break the remaining up using text processing or you can pass the resulting string as the first parameter to textscan replacing the fid parameter.

Related Solutions

MATLAB: Identifying positions of a string within a text file

Probably something like this:

fid = fopen(FileName,'rt');
filetext = fread(fid,'*char');
fclose(fid);
newtext = regexprep(filetext, '\$\$', 'Hello', 'once');
newtext = regexprep(newtext, '\$\$', 'World', 'once');
fid = fopen(NewFilename, 'wt');
fwrite(fid, newtext, '*char');
fclose(fid);

MATLAB: Regular expressions resources and regular expression problem

1. Read here about the Regular Expressions

str = 'cos(exp(a_2/4*d_1^3-ee_4)+d_85)';
fun = regexp(str,'\w*(?=\()','match')
var = regexp(str,'(a|d|ee)_\d*','match')

Best Answer

Related Solutions

MATLAB: Identifying positions of a string within a text file

MATLAB: Regular expressions resources and regular expression problem

Related Question