randomWalker2D

#python code

import random;

import time;

import os;

steps=10;

startx=0;

starty=0;

currentPosX=startx+steps;

currentPosY=starty+steps;

N=2*steps+1;

Matrix = [[0 for x in xrange(N)] for x in xrange(N)];

# this matrix is for a 2d array representing

# if the position was walked visited in the RW or not

def printMatrix(x, y):

matString="";

for i in xrange(N):

for j in xrange(N):

if i == x and j == y :

matString=matString+" "+"\x1B[31;48m" + str(Matrix[i][j]) + "\x1B[0m";

else:

# print the visited elements in blue

if Matrix[i][j] > 0 :

matString=matString+" "+"\x1B[34;48m" +str(Matrix[i][j]) + "\x1B[0m";

else:

matString=matString+" "+str(Matrix[i][j]);

matString=matString+"\n";

print matString;

iterations=1000;

for cntr in range(iterations):

Matrix[currentPosX][currentPosY]+=1;

os.system('clear');

printMatrix(currentPosX, currentPosY);

rnd = random.randint(0,3);

if rnd == 0:

currentPosX -= 1;

elif rnd == 1:

currentPosX += 1;

elif rnd == 2:

currentPosY -= 1;

elif rnd == 3:

currentPosY += 1;

# ensure the bounds

# not keeping it perfectly uniform, but just going in the other direction if the bounds are cross -- this is a hack

if currentPosX == -1:

currentPosX = 1;

if currentPosY == -1:

currentPosY = 1;

if currentPosX == N:

currentPosX = N-2;

if currentPosY == N:

currentPosY = N-2;

time.sleep(0.1);