#!/usr/bin/env python

#

# freqresp_test.py - test frequency response functions

# RMM, 30 May 2016 (based on timeresp_test.py)

#

# This is a rudimentary set of tests for frequency response functions,

# including bode plots.

import unittest

import numpy as np

from control.statesp import StateSpace

from control.matlab import ss, tf, bode

from control.exception import slycot_check

import matplotlib.pyplot as plt

class TestFreqresp(unittest.TestCase):

def setUp(self):

self.A = np.matrix('1,1;0,1')

self.C = np.matrix('1,0')

self.omega = np.linspace(10e-2,10e2,1000)

def test_siso(self):

B = np.matrix('0;1')

D = 0

sys = StateSpace(self.A,B,self.C,D)

# test frequency response

frq=sys.freqresp(self.omega)

# test bode plot

bode(sys)

# Convert to transfer function and test bode

systf = tf(sys)

bode(systf)

def test_doubleint(self):

# 30 May 2016, RMM: added to replicate typecast bug in freqresp.py

A = np.matrix('0, 1; 0, 0');

B = np.matrix('0; 1');

C = np.matrix('1, 0');

D = 0;

sys = ss(A, B, C, D);

bode(sys);

@unittest.skipIf(not slycot_check(), "slycot not installed")

def test_mimo(self):

# MIMO

B = np.matrix('1,0;0,1')

D = np.matrix('0,0')

sysMIMO = ss(self.A,B,self.C,D)

frqMIMO = sysMIMO.freqresp(self.omega)

tfMIMO = tf(sysMIMO)

#bode(sysMIMO) # - should throw not implemented exception

#bode(tfMIMO) # - should throw not implemented exception

#plt.figure(3)

#plt.semilogx(self.omega,20*np.log10(np.squeeze(frq[0])))

#plt.figure(4)

#bode(sysMIMO,self.omega)

def suite():

return unittest.TestLoader().loadTestsFromTestCase(TestTimeresp)

if __name__ == '__main__':

unittest.main()