Out of Memory using fgetl

4 vues (au cours des 30 derniers jours)
Sanket
Sanket le 3 Fév 2012
I would like to read each line of a huge text file (.txt). The text file has 3 columns of floating point number like below (about 8 million such lines in text file)
-0.02500000 -0.02450000 -0.02400000
-0.02350000 -0.02300000 -0.02250000
-0.02200000 -0.02150000 -0.02100000
My objective is to read each line at a time. Hence, I thought of using fgetl. But I get an Out of memory error when fgetl is executed for the first time
fid=fopen('allnrncoords.txt','r');
tline=fgetl(fid);
It seems fgetl is trying to read the whole file when it should just read one line. Can someone explain me what could be an issue
  1 commentaire
Walter Roberson
Walter Roberson le 3 Fév 2012
Try using 'rt' instead of 'r' in the fopen()

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Sanket
Sanket le 6 Fév 2012
The problem was in the text file I was trying to read. The text file was written using %8.8f. When I changed it to %12.8f, fgetl ran fine.

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Kevin Holst
Kevin Holst le 3 Fév 2012
Just throwing out ideas here, is your error coming at the first call to fgetl or after calling fopen?
Could it be that matlab is not recognizing an eol character in your text file and attempting to get the whole file as a line?
  3 commentaires
Kevin Holst
Kevin Holst le 3 Fév 2012
If you know that each line will always consist of 3 numbers, you could do something like:
fid=fopen('allnrncoords.txt','r');
tline=textscan(fid,'%f %f %f',1);
That will get one line of data, so you could just do that as many times as you needed.
Walter Roberson
Walter Roberson le 3 Fév 2012
Opening with 'rt' should make end of line recognition better. Unless, that is, the file happens to have been written on Mac OS (before OS-X) using only CR without LF as the line breaks.

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