#! usr/bin/perl
#This script takes multiple files that contain the same number of rows,
#and builds a matrix where the number of columns would equal the number of files.
use warnings;
use strict;
#opens all txt files in the current directory
#and stores the names of the files in @files array
opendir(FILES,".")||die "Cannot open files in the directory\n";
my @files=();
my @matrix=();
for(readdir(FILES)){
	if($_=~/\.txt/){
		push(@files, $_);
	}
}
my $n=scalar(@files);
print "This directory contains $n \.txt files\n";
#opens a file which will contain all the ratios
open(TREE,">matrix.txt");
#goes through each file in @files array
for my $i(0..$#files){
	print "Working on \.\.\. $files[$i]\.\n";
	open(FH,"<$files[$i]");
	my $j=0;
	while(my $line=<FH>){
		chomp $line;
		my @line=split("\t",$line); #This is more applicable if the file contained more than one column, tab delimited
		#@matrix is an array of array
		#jth array in @matrix contains records from different files for jth line
			push @{$matrix[$j]}, "$line[0]";
			$j++;
	}
}
for my $tmp(@matrix){
	#$records joins the elements by tab
	my $records=join "\t", @$tmp;
	print TREE "$records\n";
}
exit;