#!/usr/bin/env python
#
# Copyright 2004,2007,2010,2012,2013 Free Software Foundation, Inc.
#
# This file is part of GNU Radio
#
# GNU Radio is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3, or (at your option)
# any later version.
#
# GNU Radio is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GNU Radio; see the file COPYING.  If not, write to
# the Free Software Foundation, Inc., 51 Franklin Street,
# Boston, MA 02110-1301, USA.
#

from __future__ import division

import math

from gnuradio import gr, gr_unittest, analog, blocks

def sincos(x):
    return  math.cos(x) + math.sin(x) * 1j


class test_frequency_modulator(gr_unittest.TestCase):

    def setUp(self):
        self.tb = gr.top_block()

    def tearDown(self):
        self.tb = None

    def test_fm_001(self):
        pi = math.pi
        sensitivity = pi / 4
        src_data = (1.0 / 4, 1.0 / 2, 1.0 / 4, -1.0 / 4, -1.0 / 2, -1 / 4.0)
        running_sum = (pi / 16, 3*pi/16, pi / 4, 3*pi/16, pi / 16, 0)
        expected_result = tuple([sincos(x) for x in running_sum])
        src = blocks.vector_source_f(src_data)
        op = analog.frequency_modulator_fc(sensitivity)
        dst = blocks.vector_sink_c()
        self.tb.connect(src, op)
        self.tb.connect(op, dst)
        self.tb.run()
        result_data = dst.data()
        self.assertComplexTuplesAlmostEqual(expected_result, result_data, 5)

if __name__ == '__main__':
    gr_unittest.run(test_frequency_modulator, "test_frequency_modulator.xml")

