#!/usr/bin/perl -w
use strict;

#purpose: find simple fractions that are close to percentages...

#divisions, tolerance
my $div = 1000;
my $tol = 0.005;
my $high = 25;
my $file = 'tolerance.txt';

my $last = ''; 				#no duplicate fractions in output

open FILE, ">$file" or die;
DIV:for (1 .. $div) {
	my $val = $_ / $div;		#0.001, for example
	for ( 1 .. $high) {
		my $den = $_;		#denominator

		for (1 .. $den) {	#numerator
			my $here = $_/$den; #number

			#check for within tolerance of value
			if (($val-$tol <= $here) and ($here <= $val + $tol)) {
				my $test = "$_/$den"; #string
				if ($last ne $test) {	#unique fractions only
					$last = $test;
					print FILE "$val:\t$test\n";
				}
				next DIV;	#avoid 1/1, .. 5/5 for 1.000
			}
		}
	}
}
close FILE;

##</code><code>##

0.035:  1/25
0.037:  1/24
0.039:  1/23
0.041:  1/22
0.043:  1/21
0.046:  1/20
0.048:  1/19