Fetching indices of a text file from another text file - arrays

Question

The title may not be so descriptive. Let me explain:
I have a file (Say File 1) having some numbers [delimited by a space]. see here,
1 2 3 4 5
1 2 8 4 5 6 7
1 9 3 4 5 6 7 8
..... n lines (length of each line varies).
I have another file (Say File 2) having some numbers [delimited by a tab]. see here,
1 1 1 1 1 1 0 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 0 1 1 1 1 1
1 1 1 1 1 1 0 1 1 1 1 1
..... m lines (length of each line fixed).
I want sum of 1 2 3 4 5 th (file 1 Line 1) position of file 2, line 1
I want sum of 1 2 3 4 5 6 7 th (file 1 Line 2) position of file 2, line 1 and so on.
I want linewise sum of file 2 with positions all lines in file 1
It will look like:
5 6 6 …n columns (File 1)
1 8 3
9 8 4
… m rows (File 2)
I did this by the following code:
open( FH1, "File1.txt" );
#index = <FH1>;
open( FH2, "File2.txt" );
#matrix = <FH2>;
open( OUTPUT, ">sum.txt" );
foreach $xx (#matrix) {
#k1 = split( /\t/, "$xx" );
foreach $yy (#index) {
#k2 = split( / /, "$yy" );
$ssum = 0;
foreach $zz (#k2) {
$zz1 = $zz - 1;
if ( $k1[$zz1] == 1 ) {
$ssum++;
}
}
printf OUTPUT"$ssum\t";
$ssum = 0;
}
print OUTPUT"\n";
}
close FH1;
close FH2;
close OUTPUT;
It works absolutely fine except that, the time time requirement is enormous for large files. (e.g. 1000 lines File 1 X 25000 lines File 2 : The time is 8 minutes .
My data may exceed 4 times this example. And it's unacceptable for my users.
How to accomplish this, consuming much lesser time. or by Any other concept.

Answer 1

Always include use strict; and use warnings; in every PERL script.
You can simplify your script by not processing the first file multiple times. Also, you coding style is very outdated. You use with some lessons from Modern Perl Book by chromatic.
The following is your script simplified to take advantage of more modern style and techniques. Note, that it currently loads the file data from inside the script instead of external sources:
use strict;
use warnings;
use autodie;
use List::Util qw(sum);
my #indexes = do {
#open my $fh, '<', "File1.txt";
open my $fh, '<', \ "1 2 3 4 5\n1 2 8 4 5 6 7\n1 9 3 4 5 6 7 8\n";
map { [map {$_ - 1} split ' '] } <$fh>
};
#open my $infh, '<', "File2.txt";
my $infh = \*DATA;
#open my $outfh, '>', "sum.txt";
my $outfh = \*STDOUT;
while (<$infh>) {
my #vals = split ' ';
print $outfh join(' ', map {sum(#vals[#$_])} #indexes), "\n";
}
__DATA__
1 1 1 1 1 1 0 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 0 1 1 1 1 1
1 1 1 1 1 1 0 1 1 1 1 1
Outputs:
5 6 7
5 7 8
5 6 7
5 6 7