Python全面分析系统的时域特性和频率域特性

#!/usr/bin/env python2
# -*- coding: utf-8 -*-
"""
Created on Wed Nov 16 17:48:02 2016

@author: kindy
"""

from control import *
from scipy import signal as sgl
from matplotlib import pyplot as plt
import numpy as np

T=np.mgrid[0:8:0.02]
U1=T
U2=T**2


sys1 = tf([1],[0.5,1]) # 
sys2 = tf([2],[1,2,4]) # 

# Step Response
def step_resp():
 sout1,stime1 = step(sys1)
 sout2,stime2 = step(sys2)
 plt.plot(stime1,sout1,'b',linewidth=0.5)
 plt.plot(stime2,sout2,'b',linewidth=0.5)
 plt.xlabel("Time")
 plt.ylabel("Amplitude")
 plt.title("Step Resopnse",fontsize=12)
 #plt.legend()
 plt.show()

# Impulse Response
def impulse_resp():

 iout1,itime1 = impulse(sys1)
 iout2,itime2 = impulse(sys2)
 plt.plot(itime1,iout1,'m',linewidth=0.8)
 plt.plot(itime2,iout2,'r',linewidth=0.8)
 plt.show()

#impulse_resp()

# 任意输入信号的输出，lsim
def lsim_plot():
 yout1,Time1, xout1 = lsim(sys1, U1, T)
 yout2,Time2, xout2 = lsim(sys2, U1, T)
 plt.plot(Time1, yout1, 'b', linewidth=0.7)
 plt.plot(Time2, yout2, 'b', linewidth=0.7)
 plt.show()

#lsim_plot()

# 波特图
def bode_plot():
 bode(sys1)
 bode(sys2)

#bode_plot()

# Nyquist图
def nyquist_plot():
 nyquist(sys1)
 nyquist(sys2)

#nyquist_plot() 


# 根轨迹
def root_locus():
 rlocus(sys1)
 rlocus(sys2)

root_locus()