#!/usr/bin/env python

#

# rlocus_test.py - unit test for root locus diagrams

# RMM, 1 Jul 2011

import unittest

import numpy as np

from control.rlocus import root_locus

from control.xferfcn import TransferFunction

from control.statesp import StateSpace

from control.bdalg import feedback

class TestRootLocus(unittest.TestCase):

"""These are tests for the feedback function in rlocus.py."""

def setUp(self):

"""This contains some random LTI systems and scalars for testing."""

# Two random SISO systems.

self.sys1 = TransferFunction([1, 2], [1, 2, 3])

self.sys2 = StateSpace([[1., 4.], [3., 2.]], [[1.], [-4.]],

[[1., 0.]], [[0.]])

def testRootLocus(self):

"""Basic root locus plot"""

klist = [-1, 0, 1]

rlist = root_locus(self.sys1, [-1, 0, 1], Plot=False)

for k in klist:

np.testing.assert_array_almost_equal(

np.sort(rlist[k]),

np.sort(feedback(self.sys1, klist[k]).pole()))

def suite():

return unittest.TestLoader().loadTestsFromTestCase(TestRootLocus)

if __name__ == "__main__":

unittest.main()