In this case, equality is determined by two values being approximately equal, with a difference no greater than 0.000001 between the two values.

0.000001 is a threshold.

Since you may be dealing with numbers of arbitrary precision it's best to use Math::Decimal for performing arithmetic. 
use strict;
use warnings;

use File::Slurp;
use Math::Decimal;

my $THRESHOLD = '0.000001';
my ($FILE_1, $FILE_2) = ('file1.txt', 'file2.txt');

my $contents = { };

foreach my $file ($FILE_1, $FILE_2) {
        foreach ( (File::Slurp::read_file($file)) ) { 
                chomp;
                push @{ $contents->{$file} }, (split /\s+/, $_) 
        }
}

foreach my $val_1 ( @{ $contents->{$FILE_1} } ) { 
        my $diff = Math::Decimal::dec_sub(
                $val_1, 
                ( shift @{ $contents->{$FILE_2} } ),
        );

        my $abs_diff = Math::Decimal::dec_abs($diff);
        my $cmp      = Math::Decimal::dec_cmp( $abs_diff, $THRESHOLD )
+;

        die "Files NOT equal !!\n" if ($cmp > 0); 
}

print "Files ARE equal !!\n";

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In reply to Re: A small question on file comparison by bluestar
in thread A small question on file comparison by pavanvidem

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