Add sequential implementation
This commit is contained in:
commit
52ff979931
|
@ -0,0 +1 @@
|
|||
*.csv
|
|
@ -0,0 +1,13 @@
|
|||
[[source]]
|
||||
name = "pypi"
|
||||
url = "https://pypi.org/simple"
|
||||
verify_ssl = true
|
||||
|
||||
[dev-packages]
|
||||
|
||||
[packages]
|
||||
matplotlib = "*"
|
||||
scipy = "*"
|
||||
|
||||
[requires]
|
||||
python_version = "3"
|
|
@ -0,0 +1,129 @@
|
|||
#! /usr/bin/env python
|
||||
# -*- coding: utf-8 -*-
|
||||
# vim:fenc=utf-8 et
|
||||
|
||||
|
||||
import argparse
|
||||
import numpy as np
|
||||
import csv
|
||||
from scipy.integrate import odeint
|
||||
|
||||
|
||||
DEFAULT_RESOLUTION = 6
|
||||
DEFAULT_TMAX = 30
|
||||
DEFAULT_DT = 0.01
|
||||
|
||||
DEFAULT_L1 = 1
|
||||
DEFAULT_L2 = 1
|
||||
DEFAULT_M1 = 1
|
||||
DEFAULT_M2 = 1
|
||||
|
||||
# The gravitational acceleration (m.s-2).
|
||||
g = 9.81
|
||||
|
||||
|
||||
def deriv(y, t, L1, L2, m1, m2):
|
||||
"""Return the first derivatives of y = theta1, z1, theta2, z2."""
|
||||
theta1, z1, theta2, z2 = y
|
||||
|
||||
c, s = np.cos(theta1 - theta2), np.sin(theta1 - theta2)
|
||||
|
||||
theta1dot = z1
|
||||
z1dot = (m2 * g * np.sin(theta2) * c - m2 * s * (L1 * z1**2 * c + L2 * z2**2) - (m1 + m2) * g * np.sin(theta1)) / L1 / (m1 + m2 * s**2)
|
||||
theta2dot = z2
|
||||
z2dot = ((m1 + m2) * (L1 * z1**2 * s - g * np.sin(theta2) + g * np.sin(theta1) * c) + m2 * L2 * z2**2 * s * c) / L2 / (m1 + m2 * s**2)
|
||||
return theta1dot, z1dot, theta2dot, z2dot
|
||||
|
||||
|
||||
def solve(L1, L2, m1, m2, tmax, dt, y0):
|
||||
t = np.arange(0, tmax + dt, dt)
|
||||
|
||||
# Do the numerical integration of the equations of motion
|
||||
y = odeint(deriv, y0, t, args=(L1, L2, m1, m2))
|
||||
theta1, theta2 = y[:, 0], y[:, 2]
|
||||
|
||||
# Convert to Cartesian coordinates of the two bob positions.
|
||||
x1 = L1 * np.sin(theta1)
|
||||
y1 = -L1 * np.cos(theta1)
|
||||
x2 = x1 + L2 * np.sin(theta2)
|
||||
y2 = y1 - L2 * np.cos(theta2)
|
||||
|
||||
return theta1, theta2, x1, y1, x2, y2
|
||||
|
||||
|
||||
def gen_simulation_model_params(theta_resolution):
|
||||
search_space = np.linspace(0, 2 * np.pi, theta_resolution)
|
||||
for theta1_init in search_space:
|
||||
for theta2_init in search_space:
|
||||
yield theta1_init, theta2_init
|
||||
|
||||
|
||||
def simulate_pendulum(theta_resolution, dt=DEFAULT_DT, tmax=DEFAULT_TMAX, L1=DEFAULT_L1, L2=DEFAULT_L2, m1=DEFAULT_M1, m2=DEFAULT_M2):
|
||||
for theta1_init, theta2_init in gen_simulation_model_params(theta_resolution):
|
||||
# Initial conditions: theta1_init, dtheta1_init/dt, theta2_init, dtheta2_init/dt.
|
||||
y0 = np.array([theta1_init, 0, theta2_init, 0])
|
||||
|
||||
theta1, theta2, x1, y1, x2, y2 = solve(L1, L2, m1, m2, tmax, dt, y0)
|
||||
yield theta1_init, theta2_init, theta1, theta2, x1, y1, x2, y2
|
||||
|
||||
|
||||
def convert_results(results):
|
||||
for r in results:
|
||||
yield {
|
||||
'theta1_init': r[0],
|
||||
'theta2_init': r[1],
|
||||
'theta1': r[2][-1],
|
||||
'theta2': r[3][-1],
|
||||
}
|
||||
|
||||
|
||||
def write_csv(file_name, results):
|
||||
with open(file_name, 'w', newline='') as csvfile:
|
||||
fieldnames = ['theta1_init', 'theta2_init', 'theta1', 'theta2']
|
||||
writer = csv.DictWriter(csvfile, fieldnames=fieldnames, delimiter=',')
|
||||
writer.writeheader()
|
||||
writer.writerows(results)
|
||||
|
||||
|
||||
def main():
|
||||
parser = argparse.ArgumentParser()
|
||||
parser.add_argument(
|
||||
'results_file',
|
||||
help="Filename where the results will be stored, in CSV format"
|
||||
)
|
||||
parser.add_argument(
|
||||
'-r',
|
||||
'--resolution',
|
||||
metavar='NUM',
|
||||
type=int,
|
||||
default=DEFAULT_RESOLUTION,
|
||||
help="Resolution, %d by default" % DEFAULT_RESOLUTION
|
||||
)
|
||||
parser.add_argument(
|
||||
'--tmax',
|
||||
metavar='NUM',
|
||||
type=float,
|
||||
default=DEFAULT_TMAX,
|
||||
help="Simulation time, %f by default" % DEFAULT_TMAX
|
||||
)
|
||||
parser.add_argument(
|
||||
'--dt',
|
||||
metavar='NUM',
|
||||
type=float,
|
||||
default=DEFAULT_DT,
|
||||
help="Simulation time step, %f by default" % DEFAULT_DT
|
||||
)
|
||||
args = parser.parse_args()
|
||||
results = simulate_pendulum(
|
||||
theta_resolution=args.resolution,
|
||||
dt=args.dt,
|
||||
tmax=args.tmax,
|
||||
)
|
||||
converted_results = convert_results(results)
|
||||
|
||||
write_csv(args.results_file, converted_results)
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
main()
|
||||
|
Loading…
Reference in New Issue