Haar (python)

De GirinoWiki

#!/usr/bin/python
# coding: utf-8
 
def haar_transform(S):
    M = []
    D = []
    for i in range(0, len(S), 2):
        m = (S[i] + S[i+1]) / 2.0
        d = (S[i] - S[i+1]) / 2.0
        M = M + [m]
        D = D + [d]
    return (M, D)
 
def haar_inverse(M, D):
    S = []
    for i in range(0, len(M)):
        s1 = M[i] + D[i]
        s2 = M[i] - D[i]
        S = S + [s1, s2]
    return S
 
S = [5,3]
(M,D) = haar_transform(S)
print M, D
print haar_inverse(M, D)
S = [1,0,2,9,3,8,4,7,5,6]
(M,D) = haar_transform(S)
print M, D
print haar_inverse(M, D)