Re: reading ascii matrix

[Alex Verstak]

Add this header to your file and read it with Octave's load:

# name: x
# type: matrix
# rows: 2800000
# columns: 2

For a dataset of this size, C is probably better...

=alex


On Fri, 9 Feb 2001, Ben Bauer wrote:

> Info:
> Octave, version 2.1.9 (i686-pc-linux-gnu). 
> (PIII 550 with 256M ram)
> Linux  2.2.16
> egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)  
> 
> 
> 
> I have a plain ascii file of 2 columns and
> approx 2.8 million rows that I need to do some
> statistics on. In my octave script I have 
>   
>  for i=1:p
>   [a(i),b(i)]=fscanf(myfile,"%f %f","C"); 
>   ...
> 
> where p is the number of records in the file.
> 
> 
> This program has been reading in the data for
> 2 days now.  Currently just less than half the
> data are read in according to a print command I
> have in the loop.  There must be a better way!
> The the entire script runs in about 1.5 minutes
> for a shorter file of 20000 data pairs, with the
> majority of the time taken in reading the data.
> 
> 
> 
> Any useful suggestions would be appreciated.  Thanks.
> 
> 
> 
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