Python3 monte carlo

CONTRIBUTORS.md

@@ -5,3 +5,4 @@ Gathros
 Jeremie Gillet (- Jie -)
 Salim Khatib
 Hitesh C
+name

chapters/monte_carlo/code/Python3/monte_carlo.py

@@ -0,0 +1,34 @@
+import random
+import math
+
+
+def in_circle(x, y, r):
+    """
+    return True if (x,y) is inside a circle with radius r
+    :param x: int or float, x position of a point
+    :param y: int or float, y position of a point
+    :param r: int or float, radius of circle
+    :return: True or false
+    """
+    return x ** 2 + y ** 2 < r ** 2
+
+
+def monte_carlo(n, r):
+    """
+    calculate pi
+    :param n: int, number of points
+    :param r: radius of circle
+    :return: estimate of pi,
+    """
+    points_in_circle = 0
+    for _dummy in range(n):
+        x = random.random()
+        y = random.random()
+        if in_circle(x, y, r):
+            points_in_circle += 1
+
+    pi_estimate = 4.0 * points_in_circle / (n * r ** 2)
+    pi_erro = 100*(math.pi - pi_estimate)/math.pi
+    return pi_estimate, pi_erro
+
+print(monte_carlo(10000000, 0.5))