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Merge branch 'week10' of https://github.com/nuttamas/rse-classwork-2020 into week10
2 parents 26489ae + 7fcf3b8 commit 26b5b8c

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‎week10/calc_pi.py

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import argparse
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import math
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import random
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import timeit
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from utils import format_time
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def point_in_circle(x, y, radius=1):
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"""
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Checks whether a point (x, y) is part of a circle with a set radius.
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example
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-------
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>>> point_in_circle(0, 0)
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True
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"""
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r = math.sqrt(x ** 2 + y ** 2)
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return r <= radius
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def calculate_pi_timeit(points):
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"""
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Wrapper function to build calculate_pi with a particular number of points
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and returns the function to be timed.
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"""
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def calculate_pi():
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"""
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Calculates an approximated value of pi by the Monte Carlo method.
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"""
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within_circle = [point_in_circle(random.random(), random.random())
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for _ in range(points)]
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return 4 * sum(within_circle)/points
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return calculate_pi
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def command():
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"""
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entry point of the script to accept arguments
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"""
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parser = argparse.ArgumentParser(description="Calculates an approximate value of PI and how long it takes",
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formatter_class=argparse.ArgumentDefaultsHelpFormatter)
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parser.add_argument('--npoints', '-np', default=10_000, type=int, help="Number of random points to use")
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parser.add_argument('--number', '-n', default=100, type=int, help="Number of times to execute the calculations")
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parser.add_argument('--repeat', '-r', default=5, type=int, help="How many times to repeat the timer")
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arguments = parser.parse_args()
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calc_pi = calculate_pi_timeit(arguments.npoints)
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print(f"pi = {calc_pi()} (with {arguments.npoints})")
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result = timeit.repeat(calc_pi, number=arguments.number, repeat=arguments.repeat)
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best = min(result) / arguments.number
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print(f"{arguments.number} loops, best of {arguments.repeat}: {format_time(best)} per loop")
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if __name__ == '__main__':
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command()

‎week10/calc_pi_cython.ipynb

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{
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"cells": [
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"# Using Cython in a Jupyter notebook\n",
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"\n",
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"To use Cython, we must first load an extension."
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"%load_ext cython"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"We can define our functions with pure Python code, and Cython will try to optimise them."
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"%%cython --annotate\n",
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"import argparse\n",
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"import math\n",
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"import random\n",
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"import time\n",
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"\n",
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"from utils import format_time\n",
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"\n",
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"def point_in_circle(x, y, radius=1):\n",
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" \"\"\"\n",
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" Checks whether a point (x, y) is part of a circle with a set radius.\n",
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" example\n",
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" -------\n",
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" >>> point_in_circle(0, 0)\n",
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" True\n",
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" \"\"\"\n",
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" r = math.sqrt(x ** 2 + y ** 2)\n",
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" return r <= radius\n",
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"\n",
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"def calculate_pi(points):\n",
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" \"\"\"\n",
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" Calculates an approximated value of pi by the Monte Carlo method.\n",
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" \"\"\"\n",
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" within_circle = 0\n",
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" for _ in range(points):\n",
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" within_circle += int(point_in_circle(random.random(), random.random()))\n",
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" return 4 * within_circle/points"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"%%timeit\n",
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"number_points = 10000\n",
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"calculate_pi(number_points)"
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]
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}
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],
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"metadata": {
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"kernelspec": {
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"display_name": "Python 3",
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"language": "python",
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"name": "python3"
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},
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"language_info": {
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"codemirror_mode": {
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"name": "ipython",
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"version": 3
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},
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"file_extension": ".py",
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"mimetype": "text/x-python",
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"name": "python",
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"nbconvert_exporter": "python",
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"pygments_lexer": "ipython3",
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"version": "3.8.3"
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}
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},
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"nbformat": 4,
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"nbformat_minor": 4
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}

‎week10/calc_pi_mpi.py

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import argparse
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import random
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from mpi4py import MPI
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from calc_pi import point_in_circle, calculate_pi_timeit
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from utils import format_time
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COMM = MPI.COMM_WORLD
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SIZE = COMM.Get_size()
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RANK = COMM.Get_rank()
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if RANK == 0:
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parser = argparse.ArgumentParser(description="PI value approximated using monte-carlo and MPI")
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parser.add_argument('--npoints', '-np', default=10_000, type=int, help="Number of random points to use")
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arguments = parser.parse_args()
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print(arguments.npoints)
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points = arguments.npoints // SIZE
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extra = arguments.npoints % SIZE
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else:
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points = None
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points = COMM.bcast(points, root=0)
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if RANK == 0:
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points += extra
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WT = MPI.Wtime()
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within_circle = [point_in_circle(random.random(), random.random())
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for _ in range(points)]
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all_pi = COMM.gather(within_circle, root=0)
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if RANK == 0:
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pi = 4 * sum(map(sum, all_pi)) / arguments.npoints
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print(f"pi = {pi} (with {sum(map(len, all_pi))} points)")
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WT = MPI.Wtime() - WT
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print(f"It took: {format_time(WT)}")

‎week10/calc_pi_numba.py

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import argparse
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import math
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import random
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import time
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from numba import jit
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from utils import format_time
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@jit(nopython=True)
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def point_in_circle(x, y, radius=1):
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"""
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Checks whether a point (x, y) is part of a circle with a set radius.
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example
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-------
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>>> point_in_circle(0, 0)
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True
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"""
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r = math.sqrt(x ** 2 + y ** 2)
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return r <= radius
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@jit(nopython=True)
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def calculate_pi(points):
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"""
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Calculates an approximated value of pi by the Monte Carlo method.
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"""
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within_circle = 0
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for _ in range(points):
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within_circle += int(point_in_circle(random.random(), random.random()))
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return 4 * within_circle/points
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def command():
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"""
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entry point of the script to accept arguments
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"""
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parser = argparse.ArgumentParser(description="Calculates an approximate value of PI and how long it takes",
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formatter_class=argparse.ArgumentDefaultsHelpFormatter)
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parser.add_argument('--npoints', '-np', default=10_000, type=int, help="Number of random points to use")
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arguments = parser.parse_args()
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start = time.time()
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pi = calculate_pi(arguments.npoints)
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end = time.time()
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print(f"Elapsed (with compilation) = {format_time(end-start)}")
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print(f"pi = {pi} (with {arguments.npoints})")
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start = time.time()
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pi = calculate_pi(arguments.npoints)
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end = time.time()
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print(f"Elapsed (after compilation) = {format_time(end-start)}")
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print(f"pi = {pi} (with {arguments.npoints})")
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if __name__ == '__main__':
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command()

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