Re: what's a fast way to read ascii data?

Well, I don't know about your particular files, but I've often been able to get a file reader working acceptably by reading the entire file as a character array and then tokenizing the entire string at once using the string processing functions and then processing the tokens in a while loop. Here's an excerpt from some code I've written:

pid = fopen( path, "r" );
tok = regexp( fread(pid, "*char")', "\"([^\"]+)\"|([^\\s]+)", "match" );
fclose(pid);

For the files this code reads, the EOL's didn't matter, and the regular expression needed to pull in "strings inside quotations" as single objects.

You could probably concoct a regular expression to extract lines with four numbers from the input. Here's a regexp that will extract four integers separated by whitespace that works on the file example you posted:

fid = fopen("data.txt","r") ;
tok = regexp( fread(fid, "*char")', '\s*(\d+\s*){4}\n', "match" );
fclose( fid );

See http://www.gnu.org/software/octave/doc/interpreter/Manipulating-Strings.html for other ideas about manipulating strings.


--judd






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