BSP - Monday 7 May - some tests

patissier2.py

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.cm as cm

def create_data(n):
    data = np.reshape(range(n**2),(n,n))
    data = data[:,:,np.newaxis]
    print '-'*40
    print data[:,:,0],data.shape
    print '-'*40
    return data

def fold(data,seq):
    """fold a 3D table using the sequence seq as:
    0 : up/down
    1 : down/up
    2 : left/right
    3 : right/left
    """

    if len(seq) == 0:
        r = data
    else:
        if seq[0]==0:
            n2 = data.shape[0]/2
            dfold = np.dstack((data[n2-1::-1,:],data[n2:,:]))
            r = fold(dfold,seq[1:])

        if seq[0]==1:
            n2 = data.shape[0]/2
            dfold = np.dstack((data[:n2-1:-1,:],data[:n2,:]))
            r = fold(dfold,seq[1:])

        if seq[0]==2:
            n2 = data.shape[1]/2
            dfold = np.dstack((data[:,n2-1::-1],data[:,n2:]))
            r = fold(dfold,seq[1:])

        if seq[0]==3:
            n2 = data.shape[1]/2
            dfold = np.dstack((data[:,:n2-1:-1],data[:,:n2]))
            r = fold(dfold,seq[1:])

    return r

print 'basic tests'

data = create_data(2)

for s in range(4):
    r = fold(data,[s])
    print 'apply ',s,'-->',r.shape
    print r[:,:,0]
    print r[:,:,1]


from itertools import permutations

seq = [0,1,2,3]
test = [12, 15,  0,  3, 13, 14,  1,  2,  8, 11,  4,  7,  9, 10,  5,  6]
#test = [2, 1, 13, 14, 15, 12, 0, 3, 7, 4, 8, 11, 10, 9, 5, 6]

data = create_data(4)
print 'test=',test

for c in permutations(seq,4):
    r = fold(data,c)
    print c,'-->', r.flatten(), (r.flatten() == np.asarray(test)).all()