Out of Memory using fgetl

Question

Sanket 2012-2-3

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/27978-out-of-memory-using-fgetl

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 个评论
显示 -1更早的评论隐藏 -1更早的评论

Walter Roberson 2012-2-3

Try using 'rt' instead of 'r' in the fopen()

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Sanket 2012-2-6

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/27978-out-of-memory-using-fgetl#answer_36426

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.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

Kevin Holst 2012-2-3

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/27978-out-of-memory-using-fgetl#answer_36247

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 个评论
显示 1更早的评论隐藏 1更早的评论

Kevin Holst 2012-2-3

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 2012-2-3

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.

请先登录，再进行评论。