#!/usr/bin/python
"""This little guy figures out the best ratio of integers to achieve some rational number.
This is useful for machines without floating point, or for designing digital phase locked loops.
Pat Beirne, (c) 2009
released under GPL2
"""
import os, cgi, cgitb
form = cgi.FieldStorage()
print("Content-type: text/html\n")
print("results")
print("
Results
")
# just testing..........
#f = 3.1415926535897932384626433832
f = float(form.getvalue('ratio'))
max_i = int(form.getvalue('max_i'))
e_max = 1
e_2nd_max = 1
i_hit = -1
d_hit = -1
# check every denominator
for i in range(2,max_i):
m = f*i
d = round(m)
e = abs((m-d)/m)
if (eBest match")
print("
")
print("
Target ratio:
%.10f
" % f)
print("
Best integer ratio:
%d / %d
" % (d_hit, i_hit))
print("
Integer ratio:
%.10f (%f%% error from target)
" % (float(d_hit)/float(i_hit), e_max*100))
if i_2nd_best != -1:
print("
2nd best match
")
print("
")
print("
Target ratio:
%.10f
" % f)
print("
2nd best integer ratio:
%d / %d
" % (d_2nd_best,i_2nd_best))
e = abs(1-float(d_2nd_best)/float(i_2nd_best)/f)
print("