def test_chopping(self):
""" Test that the window function with trailing zeros chops the time series window """
# Chopping at the start
window_function_str = """lambda n: lambda x: 0 if x < 2 else 1"""
node = window_func.WindowFuncNode(
window_function_str=window_function_str, reduce_window=True)
windowed_time_series = node.execute(self.test_time_series)
self.assert_(windowed_time_series.shape[0] +
2 == self.test_time_series.shape[0])
self.assert_(
numpy.all(
windowed_time_series.view(numpy.ndarray) ==
self.test_time_series.view(numpy.ndarray)[2:, :]))
# Chopping at the end
window_function_str = """lambda n: lambda x: 0 if x >= n - 2 else 1"""
node = window_func.WindowFuncNode(
window_function_str=window_function_str, reduce_window=True)
windowed_time_series = node.execute(self.test_time_series)
self.assert_(windowed_time_series.shape[0] +
2 == self.test_time_series.shape[0])
self.assert_(
numpy.all(
windowed_time_series.view(numpy.ndarray) ==
self.test_time_series.view(numpy.ndarray)[:-2, :]))
def test_zero_window(self):
""" Test that the window function [0 0 ... 0 0] raises an InvalidWindowException """
window_function_str = "lambda n: lambda x: 0"
node = window_func.WindowFuncNode(window_function_str = window_function_str)
self.assertRaises(window_func.InvalidWindowException,
node.execute, self.test_time_series)
def test_one_window(self):
""" Test that the window function [1 1 ... 1 1] does not change the time series """
window_function_str = "lambda n: lambda x: 1"
node = window_func.WindowFuncNode(window_function_str = window_function_str)
windowed_time_series = node.execute(self.test_time_series)
self.assert_(numpy.all(windowed_time_series.view(numpy.ndarray) == self.test_time_series.view(numpy.ndarray)))
def test_convolving(self):
""" Test that convolving one with a window returns the window """
window_function_str = """lambda n: lambda x: (1 - __import__("numpy").cos((x + 1) * __import__("numpy").pi/n))/2"""
window_function = eval(window_function_str)
window = numpy.array([window_function(self.test_time_series.shape[0])(i)
for i in range(self.test_time_series.shape[0])])
node = window_func.WindowFuncNode(window_function_str = window_function_str)
windowed_time_series = node.execute(self.test_time_series)
self.assert_(numpy.all(windowed_time_series.view(numpy.ndarray)[:,1] == window))