use strict;
use warnings;
use Math::Round qw/round/;
use Data::Dumper;

# function returns 1 if all arguments are integer
# zero otherwise
sub is_approximately_an_integer {
  my $eps = 0.0001;
  while( my $x = shift ) {
    # need to use "round", "int" does not work!
    return 0 if abs( $x-round($x) ) > $eps;
  }
  return 1
}

# some test cases
print "Testing...\n";
print is_approximately_an_integer( 1, 3.99999999, 5 ), "\n";
print is_approximately_an_integer( 1.2, 3.99999999, 5 ), "\n";
print is_approximately_an_integer( 1, 3.99999999, 5.0000001 ), "\n";
print is_approximately_an_integer( 1, 3.99999999, -5 ), "\n";
print is_approximately_an_integer( 1, 3.99999999, -5.1 ), "\n";
print is_approximately_an_integer( 1, 3.99999999, -5.000000001 ), "\n";
print is_approximately_an_integer( 1, -3.99999999, -5.000000001 ), "\n";
print is_approximately_an_integer( 1 ), "\n";
print is_approximately_an_integer( 1.5 ), "\n";

# what if we have hash of arrays ?
my %hash = (
	    "1,2,3" => [ 1, 3.99999999, 5 ],
	    "1,2,4" => [ 1.2, 3.99999999, 5 ],
	    "1,2,5" => [ 1, 3.99999999, 5.0000001 ],
	    # etc
);

# this returns only the arrays but lose keys
print "\nSelected arrays\n";
my @wants = grep { is_approximately_an_integer( @$_ ) } values %hash;
print Dumper( @wants );

# this returns the keys
print "\nSelected keys...\n";
my @wants = grep { is_approximately_an_integer( @{$hash{$_}} ) } keys %hash;
print Dumper( @wants );
print "...and the associated array.\n";
# and you can get the arrays as well
print Dumper( @hash{@wants} );