Walker

main.py

@@ -4,37 +4,27 @@
 
 # Python code for 2D random walk.
 # Source: https://www.geeksforgeeks.org/random-walk-implementation-python/
+
+import matplotlib.pyplot as plt
+from randomwalk import Walker
+
 import numpy
 import matplotlib.pyplot as plt
 import random
+from randomwalk import Walker
 
 # defining the number of steps
 n = 100000
 
-# creating two array for containing x and y coordinate
-# of size equals to the number of size and filled up with 0's
-x = numpy.zeros(n)
-y = numpy.zeros(n)
-
-# filling the coordinates with random variables
+walker1 = Walker(100, 100)
+walker2 = Walker(200, 200)
 for i in range(1, n):
-    val = random.randint(1, 4)
-    if val == 1:
-        x[i] = x[i - 1] + 1
-        y[i] = y[i - 1]
-    elif val == 2:
-        x[i] = x[i - 1] - 1
-        y[i] = y[i - 1]
-    elif val == 3:
-        x[i] = x[i - 1]
-        y[i] = y[i - 1] + 1
-    else:
-        x[i] = x[i - 1]
-        y[i] = y[i - 1] - 1
-
+    walker1.walk()
+    walker2.walk()
 
 # plotting the walk
 plt.title("Random Walk ($n = " + str(n) + "$ steps)")
-plt.plot(x, y)
+plt.plot(walker1.x_coords, walker1.y_coords)
+plt.plot(walker2.x_coords, walker2.y_coords)
 plt.savefig("./rand_walk_{}.png".format(n))
-plt.show()
+plt.show()

randomwalk.py

@@ -0,0 +1,50 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""__description__
+"""
+
+__author__ = "Christina Ludwig, GIScience Research Group, Heidelberg University"
+__email__ = "christina.ludwig@uni-heidelberg.de"
+
+import random
+
+
+class Walker:
+
+    def __init__(self, init_x=500, init_y=500):
+        """
+        Create walker object
+        """
+        self.x_coords = [init_x]
+        self.y_coords = [init_y]
+
+    def walk(self):
+        """
+        Walker walks one step forward in random direction
+        :return:
+        """
+        last_x = self.x_coords[-1]
+        last_y = self.y_coords[-1]
+        new_x, new_y = self.nextStep(last_x, last_y)
+        self.x_coords.append(new_x)
+        self.y_coords.append(new_y)
+
+    def nextStep(self, last_x, last_y):
+        """
+        Choose next position randomly
+        :return:
+        """
+        val = random.randint(1, 4)
+        if val == 1:
+            new_x = last_x + 1
+            new_y = last_y
+        elif val == 2:
+            new_x = last_x - 1
+            new_y = last_y
+        elif val == 3:
+            new_x = last_x
+            new_y = last_y + 1
+        else:
+            new_x = last_x
+            new_y = last_y - 1
+        return new_x, new_y