Centre Blaise Pascal » Bench4GPU

#!/usr/bin/env python

#

# Ising2D model in serial mode

#

# CC BY-NC-SA 2011 : <emmanuel.quemener@ens-lyon.fr> 

import sys

import numpy

from PIL import Image

from math import exp

from random import random

import time

import getopt

import matplotlib.pyplot as plt

import Metropolis

def Metropolis(sigma,J,B,T,iterations): 

    start=time.time()

    SizeX,SizeY=sigma.shape

    for p in xrange(0,iterations):

        # Random access coordonate

        X,Y=numpy.random.randint(SizeX),numpy.random.randint(SizeY)

        DeltaE=J*sigma[X,Y]*(2*(sigma[X,(Y+1)%SizeY]+

                                sigma[X,(Y-1)%SizeY]+

                                sigma[(X-1)%SizeX,Y]+

                                sigma[(X+1)%SizeX,Y])+B)

        if DeltaE < 0. or random() < exp(-DeltaE/T):

            sigma[X,Y]=-sigma[X,Y]

    duration=time.time()-start

    return(duration)