#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
#
# Consideriamo \phi_{0}(x) = box function
# e iteriamo per cercare di ottenere la funzione
# associata ad un filtro.
 
print " => Carico le librerie necessarie...",
from pylab import *
import time, numpy, Filtering
print "ok"
 
# Si comincia ad iterare
h = numpy.array([0.125 , 0.25, 0.25, 0.25, 0.125])
h = Filtering.DaubechiesFilterBank.lowPassFilter.GetResponse()
h = Filtering.StrangFilterBank.lowPassFilter.GetResponse()
# h = Filtering.StrangFilterBank.lowPassFilter.GetResponse()
t = numpy.linspace(-0.5,len(h) + 0.05,100)
 
def box(x):
    """box function"""
    if(x >= 0 and x<=1):
        return 1
    return 0
 
 
phi = map(box, t)
 
 
def refinement(x):
    """Refinement function"""
    i = t.tolist().index(x)
    newphi = 0
    counter = 0
    for value in h:
        newphi += value * phi_func(2*x - counter)
        counter += 1
    return max(min(2 * newphi, 10), -10)
 
def phi_func(x):
 
    for item in t:
        if item > x:
             break
    return phi[t.tolist().index(item)]
 
ion ()
hold(False)
diff = 1
try:
    while True:
        plot(t,phi)
        draw ()
        print "diff = %f" % diff
        time.sleep (1)
        newphi = map(refinement, t)
        diff = numpy.linalg.norm(numpy.array(newphi) - numpy.array(phi))
        phi = newphi
except KeyboardInterrupt:
 
    plot(t,phi)
    draw()
    raw_input()
 
    f = open("phi.txt", "w")
    for value in phi:
        f.write("%s\n" % value)
    f.close ()