GeezerVison is showing github.com — python-control/examples/plot_gallery.py at main · python-control/python-control

Expand file tree

plot_gallery.py

Copy path

More file actions

Latest commit

History

162 lines (141 loc) · 5.37 KB

plot_gallery.py

Copy path

File metadata and controls

162 lines (141 loc) · 5.37 KB

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

# plot_gallery.py - different types of plots for comparing versions

# RMM, 19 Jun 2024

# This file collects together some of the more interesting plots that can

# be generated by python-control and puts them into a PDF file that can be

# used to compare what things look like between different versions of the

# library. It is mainly intended for uses by developers to make sure there

# are no unexpected changes in plot formats, but also has some interest

# examples of things you can plot.

import os

import sys

from math import pi

import matplotlib.pyplot as plt

import numpy as np

import control as ct

# Don't save figures if we are running CI tests

savefigs = 'PYCONTROL_TEST_EXAMPLES' not in os.environ

if savefigs:

# Create a pdf file for storing the results

import subprocess

from matplotlib.backends.backend_pdf import PdfPages

from datetime import date

git_info = subprocess.check_output(['git', 'describe'], text=True).strip()

pdf = PdfPages(

f'plot_gallery-{git_info}-{date.today().isoformat()}.pdf')

# Context manager to handle plotting

class create_figure(object):

def __init__(self, name):

self.name = name

def __enter__(self):

self.fig = plt.figure()

print(f"Generating {self.name} as Figure {self.fig.number}")

return self.fig

def __exit__(self, type, value, traceback):

if type is not None:

print(f"Exception: {type=}, {value=}, {traceback=}")

if savefigs:

pdf.savefig()

if hasattr(sys, 'ps1'):

# Show the figures on the screen

plt.show(block=False)

else:

plt.close()

# Define systems to use throughout

sys1 = ct.tf([1], [1, 2, 1], name='sys1')

sys2 = ct.tf([1, 0.2], [1, 1, 3, 1, 1], name='sys2')

sys_mimo1 = ct.tf2ss(

[[[1], [0.1]], [[0.2], [1]]],

[[[1, 0.6, 1], [1, 1, 1]], [[1, 0.4, 1], [1, 2, 1]]], name="sys_mimo1")

sys_mimo2 = ct.tf2ss(

[[[1], [0.1]], [[0.2], [1]]],

[[[1, 0.2, 1], [1, 24, 22, 5]], [[1, 4, 16, 21], [1, 0.1]]],

name="sys_mimo2")

sys_frd = ct.frd(

[[np.array([10 + 0j, 5 - 5j, 1 - 1j, 0.5 - 1j, -.1j]),

np.array([1j, 0.5 - 0.5j, -0.5, 0.1 - 0.1j, -.05j]) * 0.1],

[np.array([10 + 0j, -20j, -10, 2j, 1]),

np.array([10 + 0j, 5 - 5j, 1 - 1j, 0.5 - 1j, -.1j]) * 0.01]],

np.logspace(-2, 2, 5))

sys_frd.name = 'frd' # For backward compatibility

# Close all existing figures

plt.close('all')

# bode

with create_figure("Bode plot"):

try:

ct.bode_plot([sys_mimo1, sys_mimo2])

except AttributeError:

print(" - falling back to earlier method")

plt.clf()

ct.bode_plot(sys_mimo1)

ct.bode_plot(sys_mimo2)

# describing function

with create_figure("Describing function plot"):

H = ct.tf([1], [1, 2, 2, 1]) * 8

F = ct.descfcn.saturation_nonlinearity(1)

amp = np.linspace(1, 4, 10)

ct.describing_function_response(H, F, amp).plot()

# nichols

with create_figure("Nichols chart"):

response = ct.frequency_response([sys1, sys2])

ct.nichols_plot(response)

# nyquist

with create_figure("Nyquist plot"):

ct.nyquist_plot([sys1, sys2])

# phase plane

with create_figure("Phase plane plot"):

def invpend_update(t, x, u, params):

m, l, b, g = params['m'], params['l'], params['b'], params['g']

return [x[1], -b/m * x[1] + (g * l / m) * np.sin(x[0]) + u[0]/m]

invpend = ct.nlsys(invpend_update, states=2, inputs=1, name='invpend')

ct.phase_plane_plot(

invpend, [-2*pi, 2*pi, -2, 2], 5,

plot_separatrices={'gridspec': [12, 9]},

params={'m': 1, 'l': 1, 'b': 0.2, 'g': 1})

# pole zero map

with create_figure("Pole/zero map"):

T = ct.tf(

[-9.0250000e-01, -4.7200750e+01, -8.6812900e+02,

+5.6261850e+03, +2.1258472e+05, +8.4724600e+05,

+1.0192000e+06, +2.3520000e+05],

[9.02500000e-03, 9.92862812e-01, 4.96974094e+01,

1.35705659e+03, 2.09294163e+04, 1.64898435e+05,

6.54572220e+05, 1.25274600e+06, 1.02420000e+06,

2.35200000e+05], name='T')

ct.pole_zero_plot([T, sys2])

# root locus

with create_figure("Root locus plot") as fig:

ax_array = ct.pole_zero_subplots(2, 1, grid=[True, False])

ax1, ax2 = ax_array[:, 0]

sys1 = ct.tf([1, 2], [1, 2, 3], name='sys1')

sys2 = ct.tf([1, 0.2], [1, 1, 3, 1, 1], name='sys2')

ct.root_locus_plot([sys1, sys2], ax=ax1)

ct.root_locus_plot([sys1, sys2], ax=ax2)

plt.suptitle("Root locus plots (w/ specified axes)", fontsize='medium')

# sisotool

with create_figure("sisotool"):

s = ct.tf('s')

H = (s+0.3)/(s**4 + 4*s**3 + 6.25*s**2)

ct.sisotool(H)

# step response

with create_figure("step response") as fig:

try:

ct.step_response([sys_mimo1, sys_mimo2]).plot()

except ValueError:

print(" - falling back to earlier method")

fig.clf()

ct.step_response(sys_mimo1).plot()

ct.step_response(sys_mimo2).plot()

# time response

with create_figure("time response"):

timepts = np.linspace(0, 10)

U = np.vstack([np.sin(timepts), np.cos(2*timepts)])

resp1 = ct.input_output_response(sys_mimo1, timepts, U)

U = np.vstack([np.cos(2*timepts), np.sin(timepts)])

resp2 = ct.input_output_response(sys_mimo1, timepts, U)

resp = ct.combine_time_responses(

[resp1, resp2], trace_labels=["resp1", "resp2"])

resp.plot(transpose=True)

# Show the figures if running in interactive mode

if savefigs:

pdf.close()