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Start making comprehensive calc tests

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Peter Baratta
2013-05-20 13:59:12 -04:00
parent f63a4432d0
commit 5e8d2ce4f7
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common/lib/calc/tests/test_calc.py Normal file
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"""
unittests for calc.py
Run like this:
rake test_common/lib/calc ??
"""
import unittest
import numpy
import calc
class EvaluatorTest(unittest.TestCase):
''' Run tests for calc.evaluator
Go through all functionalities as specifically as possible--
work from number input to functions and complex expressions
Also test custom variable substitutions (i.e.
`evaluator({'x':3.0},{}, '3*x')`
gives 9.0) and more.
'''
def test_number_input(self):
''' Test different kinds of float inputs '''
easy_eval = lambda x: calc.evaluator({}, {}, x)
self.assertEqual(easy_eval("13"), 13)
self.assertEqual(easy_eval("3.14"), 3.14)
self.assertEqual(easy_eval(".618033989"), 0.618033989)
self.assertEqual(easy_eval("-13"), -13)
self.assertEqual(easy_eval("-3.14"), -3.14)
self.assertEqual(easy_eval("-.618033989"), -0.618033989)
# see also test_exponential_answer
# and test_si_suffix
def test_exponential_answer(self):
''' Test for correct interpretation of scientific notation'''
answer = 50
correct_responses = ["50", "50.0", "5e1", "5e+1", "50e0", "50.0e0", "500e-1"]
incorrect_responses = ["", "3.9", "4.1", "0", "5.01e1"]
for input_str in correct_responses:
result = calc.evaluator({}, {}, input_str)
fail_msg = "Failed when checking '{0}' against {1} (expected equality)".format(
input_str, answer)
self.assertEqual(answer, result, msg=fail_msg)
for input_str in incorrect_responses:
result = calc.evaluator({}, {}, input_str)
fail_msg = "Failed when checking '{0}' against {1} (expected inequality)".format(
input_str, answer)
self.assertNotEqual(answer, result, msg=fail_msg)
def test_si_suffix(self):
''' Test calc.py's unique functionality of interpreting si 'suffixes'.
For instance 'k' stand for 'kilo-' so '1k' should be 1,000 '''
test_mapping = [('4.2%', 0.042), ('2.25k', 2250), ('8.3M', 8300000),
('9.9G', 9.9e9), ('1.2T', 1.2e12), ('7.4c', 0.074),
('5.4m', 0.0054), ('8.7u', 0.0000087),
('5.6n', 5.6e-9), ('4.2p', 4.2e-12)]
for (expr, answer) in test_mapping:
tolerance = answer * 1e-6 # Testing exactly fails for the large values
fail_msg = "Failure in testing suffix '{0}': '{1}' was not {2}".format(
expr[-1], expr, answer)
self.assertAlmostEqual(calc.evaluator({}, {}, expr), answer,
delta=tolerance, msg=fail_msg)
def test_operator_sanity(self):
''' Test for simple things like "5+2" and "5/2"'''
var1 = 5.0
var2 = 2.0
operators = [('+', 7), ('-', 3), ('*', 10), ('/', 2.5), ('^', 25)]
for (operator, answer) in operators:
input_str = "{0} {1} {2}".format(var1, operator, var2)
result = calc.evaluator({}, {}, input_str)
fail_msg = "Failed on operator '{0}': '{1}' was not {2}".format(
operator, input_str, answer)
self.assertEqual(answer, result, msg=fail_msg)
self.assertRaises(ZeroDivisionError, calc.evaluator,
{}, {}, '1/0')
def test_parallel_resistors(self):
''' Test the special operator ||
The formula is given by
a || b || c ...
= 1 / (1/a + 1/b + 1/c + ...)
It is the resistance of a parallel circuit of resistors with resistance
a, b, c, etc&. See if this evaulates correctly.'''
self.assertEqual(calc.evaluator({}, {}, '1||1'), 0.5)
self.assertEqual(calc.evaluator({}, {}, '1||1||2'), 0.4)
# I don't know why you would want this, but it works.
self.assertEqual(calc.evaluator({}, {}, "j||1"), 0.5 + 0.5j)
self.assertRaises(ZeroDivisionError, calc.evaluator,
{}, {}, '0||1')
def assert_function_values(self, fname, ins, outs, tolerance=1e-3):
''' Helper function to test many values at once
Test the accuracy of evaluator's use of the function given by fname
Specifically, the equality of `fname(ins[i])` against outs[i].
Used later to test a whole bunch of f(x) = y at a time '''
for (arg, val) in zip(ins, outs):
input_str = "{0}({1})".format(fname, arg)
result = calc.evaluator({}, {}, input_str)
fail_msg = "Failed on function {0}: '{1}' was not {2}".format(
fname, input_str, val)
self.assertAlmostEqual(val, result, delta=tolerance, msg=fail_msg)
def test_trig_functions(self):
"""Test the trig functions provided in common/lib/calc/calc.py"""
# which are: sin, cos, tan, arccos, arcsin, arctan
angles = ['-pi/4', '0', 'pi/6', 'pi/5', '5*pi/4', '9*pi/4', 'j', '1 + j']
sin_values = [-0.707, 0, 0.5, 0.588, -0.707, 0.707, 1.175j, 1.298 + 0.635j]
cos_values = [0.707, 1, 0.866, 0.809, -0.707, 0.707, 1.543, 0.834 - 0.989j]
tan_values = [-1, 0, 0.577, 0.727, 1, 1, 0.762j, 0.272 + 1.084j]
# Cannot test tan(pi/2) b/c pi/2 is a float and not precise...
self.assert_function_values('sin', angles, sin_values)
self.assert_function_values('cos', angles, cos_values)
self.assert_function_values('tan', angles, tan_values)
# include those where the real part is between -pi/2 and pi/2
arcsin_inputs = ['-0.707', '0', '0.5', '0.588', '1.298 + 0.635*j']
arcsin_angles = [-0.785, 0, 0.524, 0.629, 1 + 1j]
self.assert_function_values('arcsin', arcsin_inputs, arcsin_angles)
# rather than throwing an exception, numpy.arcsin gives nan
# self.assertTrue(numpy.isnan(calc.evaluator({}, {}, 'arcsin(-1.1)')))
# self.assertTrue(numpy.isnan(calc.evaluator({}, {}, 'arcsin(1.1)')))
# disabled for now because they are giving a runtime warning... :-/
# include those where the real part is between 0 and pi
arccos_inputs = ['1', '0.866', '0.809', '0.834-0.989*j']
arccos_angles = [0, 0.524, 0.628, 1 + 1j]
self.assert_function_values('arccos', arccos_inputs, arccos_angles)
# self.assertTrue(numpy.isnan(calc.evaluator({}, {}, 'arccos(-1.1)')))
# self.assertTrue(numpy.isnan(calc.evaluator({}, {}, 'arccos(1.1)')))
# has the same range as arcsin
arctan_inputs = ['-1', '0', '0.577', '0.727', '0.272 + 1.084*j']
arctan_angles = arcsin_angles
self.assert_function_values('arctan', arctan_inputs, arctan_angles)
def test_other_functions(self):
"""Test the other functions provided in common/lib/calc/calc.py"""
# sqrt, log10, log2, ln, abs,
# fact, factorial
# test sqrt
self.assert_function_values('sqrt',
[0, 1, 2, 1024], # -1
[0, 1, 1.414, 32]) # 1j
# sqrt(-1) is NAN not j (!!).
# test logs
self.assert_function_values('log10',
[0.1, 1, 3.162, 1000000, '1+j'],
[-1, 0, 0.5, 6, 0.151 + 0.341j])
self.assert_function_values('log2',
[0.5, 1, 1.414, 1024, '1+j'],
[-1, 0, 0.5, 10, 0.5 + 1.133j])
self.assert_function_values('ln',
[0.368, 1, 1.649, 2.718, 42, '1+j'],
[-1, 0, 0.5, 1, 3.738, 0.347 + 0.785j])
# test abs
self.assert_function_values('abs', [-1, 0, 1, 'j'], [1, 0, 1, 1])
# test factorial
fact_inputs = [0, 1, 3, 7]
fact_values = [1, 1, 6, 5040]
self.assert_function_values('fact', fact_inputs, fact_values)
self.assert_function_values('factorial', fact_inputs, fact_values)
self.assertRaises(ValueError, calc.evaluator, {}, {}, "fact(-1)")
self.assertRaises(ValueError, calc.evaluator, {}, {}, "fact(0.5)")
self.assertRaises(ValueError, calc.evaluator, {}, {}, "factorial(-1)")
self.assertRaises(ValueError, calc.evaluator, {}, {}, "factorial(0.5)")
def test_constants(self):
"""Test the default constants provided in common/lib/calc/calc.py"""
# which are: j (complex number), e, pi, k, c, T, q
# ('expr', python value, tolerance (or None for exact))
default_variables = [('j', 1j, None),
('e', 2.7183, 1e-3),
('pi', 3.1416, 1e-3),
# c = speed of light
('c', 2.998e8, 1e5),
# 0 deg C = T Kelvin
('T', 298.15, 0.01),
# note k = scipy.constants.k = 1.3806488e-23
('k', 1.3806488e-23, 1e-26),
# note q = scipy.constants.e = 1.602176565e-19
('q', 1.602176565e-19, 1e-22)]
for (variable, value, tolerance) in default_variables:
fail_msg = "Failed on constant '{0}', not within bounds".format(
variable)
result = calc.evaluator({}, {}, variable)
if tolerance is None:
self.assertEqual(value, result, msg=fail_msg)
else:
self.assertAlmostEqual(value, result,
delta=tolerance, msg=fail_msg)
def test_complex_expression(self):
"""We've only tried simple things so far, make sure it can handle a
more complexity than this."""
self.assertAlmostEqual(
calc.evaluator({}, {}, "(2^2+1.0)/sqrt(5e0)*5-1"),
10.180,
delta=1e-3)
self.assertAlmostEqual(
calc.evaluator({}, {}, "1+1/(1+1/(1+1/(1+1)))"),
1.6,
delta=1e-3)
self.assertAlmostEqual(
calc.evaluator({}, {}, "10||sin(7+5)"),
-0.567, delta=0.01)
def test_calc(self):
variables = {'R1': 2.0, 'R3': 4.0}
functions = {'sin': numpy.sin, 'cos': numpy.cos}
self.assertAlmostEqual(
calc.evaluator(variables, functions, "10||sin(7+5)"),
-0.567, delta=0.01)
self.assertEqual(calc.evaluator({'R1': 2.0, 'R3': 4.0}, {}, "13"), 13)
self.assertEqual(calc.evaluator(variables, functions, "13"), 13)
self.assertEqual(
calc.evaluator({
'a': 2.2997471478310274, 'k': 9, 'm': 8,
'x': 0.66009498411213041},
{}, "5"),
5)
self.assertEqual(calc.evaluator(variables, functions, "R1*R3"), 8.0)
self.assertAlmostEqual(calc.evaluator(variables, functions, "sin(e)"), 0.41, delta=0.01)
self.assertAlmostEqual(calc.evaluator(variables, functions, "k*T/q"), 0.025, delta=1e-3)
self.assertAlmostEqual(calc.evaluator(variables, functions, "e^(j*pi)"), -1, delta=1e-5)
variables['t'] = 1.0
self.assertAlmostEqual(calc.evaluator(variables, functions, "t"), 1.0, delta=1e-5)
self.assertAlmostEqual(calc.evaluator(variables, functions, "T"), 1.0, delta=1e-5)
self.assertAlmostEqual(calc.evaluator(variables, functions, "t", cs=True), 1.0, delta=1e-5)
self.assertAlmostEqual(calc.evaluator(variables, functions, "T", cs=True), 298, delta=0.2)
self.assertRaises(calc.UndefinedVariable, calc.evaluator,
{}, {}, "5+7 QWSEKO")
self.assertRaises(calc.UndefinedVariable, calc.evaluator,
{'r1': 5}, {}, "r1+r2")
self.assertEqual(calc.evaluator(variables, functions, "r1*r3"), 8.0)
self.assertRaises(calc.UndefinedVariable, calc.evaluator,
variables, functions, "r1*r3", cs=True)