module to calculate pi over time, via the monte carlo method.

idea pinched from #linode.

modules/Pi.py

@@ -0,0 +1,70 @@
+"""
+Pi - calculate pi over time via the monte carlo method. idea borrowed from #linode
+Copyright (C) 2010  Brian S. Stephan
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+"""
+
+from ConfigParser import NoOptionError, NoSectionError
+import math
+import random
+
+from extlib import irclib
+
+from Module import Module
+
+class Pi(Module):
+    """
+    Use the Monte Carlo method to approximate pi. Each time this method is called,
+    it calculates a random point inside a square on the xy plane. If that point also
+    falls within a circle bound within that square, it is added to the count of points
+    inside. Over time, 4 * count_inside / count approaches pi.
+
+    Idea from #linode on OFTC. Code from http://www.eveandersson.com/pi/monte-carlo-circle
+    """
+
+    def do(self, connection, event, nick, userhost, replypath, what, admin_unlocked):
+        if what == "pi":
+            try:
+                if not self.config.has_section(self.__class__.__name__):
+                    self.config.add_section(self.__class__.__name__)
+
+                # set default values if unset
+                if not self.config.has_option(self.__class__.__name__, "count_inside"):
+                    self.config.set(self.__class__.__name__, "count_inside", "0")
+                if not self.config.has_option(self.__class__.__name__, "count"):
+                    self.config.set(self.__class__.__name__, "count", "0")
+
+                # load values from config
+                count_inside    = self.config.getint(self.__class__.__name__, "count_inside")
+                count           = self.config.getint(self.__class__.__name__, "count")
+
+                x = random.random()
+                y = random.random()
+                inside = False
+                d = math.hypot(x,y)
+                if d < 1:
+                    inside = True
+                    count_inside += 1
+                count += 1
+                pi = 4.0 * count_inside / count
+
+                self.config.set(self.__class__.__name__, "count_inside", str(count_inside))
+                self.config.set(self.__class__.__name__, "count", str(count))
+
+                return self.reply(connection, replypath, "({0:.10f}, {1:.10f}) is {2}within the circle. Pi is {5:.10f} ({3:d}/{4:d}).".format(x, y, "" if inside else "not ", count_inside, count, pi));
+            except NoOptionError, NoSectionError: pass
+
+# vi:tabstop=4:expandtab:autoindent
+# kate: indent-mode python;indent-width 4;replace-tabs on;