dr.botzo/modules/Pi.py

105 lines
3.9 KiB
Python

"""
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/>.
"""
import math
import random
import sqlite3
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 db_init(self):
"""
Initialize database tables.
"""
# init the database if pi table doesn't exist
version = self.db_module_registered(self.__class__.__name__)
if version == None:
# create tables
db = self.get_db()
try:
db.execute('''
CREATE TABLE pi_log (
id INTEGER PRIMARY KEY AUTOINCREMENT,
count_inside INTEGER NOT NULL,
count_total INTEGER NOT NULL,
time TEXT DEFAULT CURRENT_TIMESTAMP
)
''')
db.execute('''
CREATE VIEW pi_latest_pi AS
SELECT count_inside, count_total
FROM pi_log
ORDER BY id DESC
''')
db.execute('INSERT INTO drbotzo_modules VALUES (?,?)', (self.__class__.__name__, 1))
db.commit()
except sqlite3.Error as e:
db.rollback()
print("sqlite error: " + str(e))
raise
def do(self, connection, event, nick, userhost, replypath, what, admin_unlocked):
if what == "pi":
db = self.get_db()
try:
cur = db.cursor()
pi_data = cur.execute('SELECT * FROM pi_latest_pi')
datum = pi_data.fetchone()
if datum == None:
count_inside = 0
count = 0
else:
# load values
count_inside = datum['count_inside']
count = datum['count_total']
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
cur.execute('INSERT INTO pi_log (count_inside, count_total) VALUES (?,?)', (count_inside, count))
db.commit()
except sqlite3.Error as e:
db.rollback()
return self.reply(connection, replypath, "sqlite error: " + str(e))
return self.reply(connection, replypath, "({0:.10f}, {1:.10f}) is {2}within the circle. pi is {5:.10f}. (i:{3:d} p:{4:d})".format(x, y, "" if inside else "not ", count_inside, count, pi));
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