fixed radius hardcoding issue

Author: GuyPozner

chapters/monte_carlo/code/python/monte_carlo.py

@@ -2,27 +2,26 @@
 import random
 
 
-def in_circle(x, y):
+def in_circle(x, y, radius = 1):
 	"""Return True if the point is in the circle and False otherwise."""
-	radius = 1.0
 	return (x*x + y*y) < radius*radius
 
-def monte_carlo(n_samples):
+def monte_carlo(n_samples, radius = 1):
 	"""Return the estimate of pi using the monte carlo algorithm."""
 	in_circle_count = 0
 	for i in range(n_samples):
 
 		# Sample x, y from the uniform distribution
-		x = random.uniform(0,1)
-		y = random.uniform(0,1)
+		x = random.uniform(0, radius)
+		y = random.uniform(0, radius)
 
 		# Count the number of points inside the circle
 		if(in_circle(x, y, radius)):
 			in_circle_count += 1
 
-	# Since we've generated points in upper left quadrant ([0,1], [0,1])
+	# Since we've generated points in upper left quadrant ([0,radius], [0, radius])
 	# We need to multiply the number of points by 4	
-	pi_estimate = 4 * in_circle_count / (n_samples * radius * radius)
+	pi_estimate = 4 * in_circle_count / (n_samples)
 
 	return pi_estimate
 

chapters/monte_carlo/monte_carlo.md

@@ -48,7 +48,7 @@ each point is tested to see whether it's in the circle or not:
 {% sample lang="d" %}
 [import:2-5, lang:"d"](code/d/monte_carlo.d)
 {% sample lang="py" %}
-[import:5-8, lang:"python"](code/python/monte_carlo.py)
+[import:5-7, lang:"python"](code/python/monte_carlo.py)
 {% sample lang="go" %}
 [import:12-14, lang:"golang"](code/go/monteCarlo.go)
 {% endmethod %}