Create File Speedily From Individual Column
- by neversaint
I have a data that looks like this:
-1 1:-0.394668 2:-0.794872 3:-1 4:-0.871341 5:0.9365 6:0.75597
1 1:-0.463641 2:-0.897436 3:-1 4:-0.871341 5:0.44378 6:0.121824
1 1:-0.469432 2:-0.897436 3:-1 4:-0.871341 5:0.32668 6:0.302529
-1 1:-0.241547 2:-0.538462 3:-1 4:-0.871341 5:0.9994 6:0.987166
1 1:-0.757233 2:-0.948718 3:-1 4:-0.871341 5:-0.33904 6:0.915401
1 1:-0.167147 2:-0.589744 3:-1 4:-0.871341 5:0.95078 6:0.991566
The first column is class, and next 6 columns are features. I want to create 6 files
for individual features. For example
feat1_file.txt will contain
-1 1:-0.394668
1 1:-0.463641
...
1 1:-0.757233
1 1:-0.167147
feat2_file.txt will contain
-1 2:-0.794872
...
1 2:-0.589744
and so on. I have a Perl code that does this but it is horribly slow. Is there
a way to do it faster? Typically the input files will contain 100K lines.
use strict;
use Data::Dumper;
use Carp;
my $input = $ARGV[0] || "myinput.txt";
my $INFILE_file_name = $input; # input file name
open ( INFILE, '<', $INFILE_file_name )
or croak "$0 : failed to open input file $INFILE_file_name : $!\n";
my $out1 = $input."_feat_1.txt";
my $out2 = $input."_feat_2.txt";
my $out3 = $input."_feat_3.txt";
my $out4 = $input."_feat_4.txt";
my $out5 = $input."_feat_5.txt";
my $out6 = $input."_feat_6.txt";
unlink($out1);
unlink($out2);
unlink($out3);
unlink($out4);
unlink($out5);
unlink($out6);
print "$out1\n";
while ( <INFILE> ) {
chomp;
my @els = split(/\s+/,$_);
my $lbl = $els[0];
my $OUTFILE1_file_name = $out1; # output file name
open ( OUTFILE1, '>>', $OUTFILE1_file_name )
or croak "$0 : failed to open output file $OUTFILE1_file_name : $!\n";
print OUTFILE1 "$lbl $els[1]\n";
close ( OUTFILE1 ); # close output file
my $OUTFILE2_file_name = $out2; # output file name
open ( OUTFILE2, '>>', $OUTFILE2_file_name )
or croak "$0 : failed to open output file $OUTFILE2_file_name : $!\n";
print OUTFILE2 "$lbl $els[2]\n";
close ( OUTFILE2 ); # close output file
# Etc.. until OUTFILE 6
}
close (INFILE);
