"""
Unit tests for calc.py
"""
import unittest
import numpy
import calc
from pyparsing import ParseException
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
See also
test_trailing_period (slightly different)
test_exponential_answer
test_si_suffix
"""
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)
def test_period(self):
"""
The string '.' should not evaluate to anything.
"""
self.assertRaises(ParseException, calc.evaluator, {}, {}, '.')
self.assertRaises(ParseException, calc.evaluator, {}, {}, '1+.')
def test_trailing_period(self):
"""
Test that things like '4.' will be 4 and not throw an error
"""
try:
self.assertEqual(4.0, calc.evaluator({}, {}, '4.'))
except ParseException:
self.fail("'4.' is a valid input, but threw an exception")
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 = "Expected '{0}' to equal {1}".format(
input_str, answer)
self.assertEqual(answer, result, msg=fail_msg)
for input_str in incorrect_responses:
result = calc.evaluator({}, {}, input_str)
fail_msg = "Expected '{0}' to not equal {1}".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 # Make rel. tolerance, because of floats
fail_msg = "Failure in testing suffix '{0}': '{1}' was not {2}"
fail_msg = fail_msg.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)
def test_raises_zero_division_err(self):
"""
Ensure division by zero gives an error
"""
self.assertRaises(ZeroDivisionError, calc.evaluator,
{}, {}, '1/0')
self.assertRaises(ZeroDivisionError, calc.evaluator,
{}, {}, '1/0.0')
self.assertRaises(ZeroDivisionError, calc.evaluator,
{'x': 0.0}, {}, '1/x')
def test_parallel_resistors(self):
"""
Test the parallel resistor 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)
self.assertEqual(calc.evaluator({}, {}, "j||1"), 0.5 + 0.5j)
def test_parallel_resistors_with_zero(self):
"""
Check the behavior of the || operator with 0
"""
self.assertTrue(numpy.isnan(calc.evaluator({}, {}, '0||1')))
self.assertTrue(numpy.isnan(calc.evaluator({}, {}, '0.0||1')))
self.assertTrue(numpy.isnan(calc.evaluator({'x': 0.0}, {}, 'x||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].
This is 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 calc.py
which are: sin, cos, tan, arccos, arcsin, arctan
"""
angles = ['-pi/4', '0', 'pi/6', 'pi/5', '5*pi/4', '9*pi/4', '1 + j']
sin_values = [-0.707, 0, 0.5, 0.588, -0.707, 0.707, 1.298 + 0.635j]
cos_values = [0.707, 1, 0.866, 0.809, -0.707, 0.707, 0.834 - 0.989j]
tan_values = [-1, 0, 0.577, 0.727, 1, 1, 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_reciprocal_trig_functions(self):
"""
Test the reciprocal trig functions provided in calc.py
which are: sec, csc, cot, arcsec, arccsc, arccot
"""
angles = ['-pi/4', 'pi/6', 'pi/5', '5*pi/4', '9*pi/4', '1 + j']
sec_values = [1.414, 1.155, 1.236, -1.414, 1.414, 0.498 + 0.591j]
csc_values = [-1.414, 2, 1.701, -1.414, 1.414, 0.622 - 0.304j]
cot_values = [-1, 1.732, 1.376, 1, 1, 0.218 - 0.868j]
self.assert_function_values('sec', angles, sec_values)
self.assert_function_values('csc', angles, csc_values)
self.assert_function_values('cot', angles, cot_values)
arcsec_inputs = ['1.1547', '1.2361', '2', '-2', '-1.4142', '0.4983+0.5911*j']
arcsec_angles = [0.524, 0.628, 1.047, 2.094, 2.356, 1 + 1j]
self.assert_function_values('arcsec', arcsec_inputs, arcsec_angles)
arccsc_inputs = ['-1.1547', '-1.4142', '2', '1.7013', '1.1547', '0.6215-0.3039*j']
arccsc_angles = [-1.047, -0.785, 0.524, 0.628, 1.047, 1 + 1j]
self.assert_function_values('arccsc', arccsc_inputs, arccsc_angles)
# Has the same range as arccsc
arccot_inputs = ['-0.5774', '-1', '1.7321', '1.3764', '0.5774', '(0.2176-0.868*j)']
arccot_angles = arccsc_angles
self.assert_function_values('arccot', arccot_inputs, arccot_angles)
def test_hyperbolic_functions(self):
"""
Test the hyperbolic functions
which are: sinh, cosh, tanh, sech, csch, coth
"""
inputs = ['0', '0.5', '1', '2', '1+j']
neg_inputs = ['0', '-0.5', '-1', '-2', '-1-j']
negate = lambda x: [-k for k in x]
# sinh is odd
sinh_vals = [0, 0.521, 1.175, 3.627, 0.635 + 1.298j]
self.assert_function_values('sinh', inputs, sinh_vals)
self.assert_function_values('sinh', neg_inputs, negate(sinh_vals))
# cosh is even - do not negate
cosh_vals = [1, 1.128, 1.543, 3.762, 0.834 + 0.989j]
self.assert_function_values('cosh', inputs, cosh_vals)
self.assert_function_values('cosh', neg_inputs, cosh_vals)
# tanh is odd
tanh_vals = [0, 0.462, 0.762, 0.964, 1.084 + 0.272j]
self.assert_function_values('tanh', inputs, tanh_vals)
self.assert_function_values('tanh', neg_inputs, negate(tanh_vals))
# sech is even - do not negate
sech_vals = [1, 0.887, 0.648, 0.266, 0.498 - 0.591j]
self.assert_function_values('sech', inputs, sech_vals)
self.assert_function_values('sech', neg_inputs, sech_vals)
# the following functions do not have 0 in their domain
inputs = inputs[1:]
neg_inputs = neg_inputs[1:]
# csch is odd
csch_vals = [1.919, 0.851, 0.276, 0.304 - 0.622j]
self.assert_function_values('csch', inputs, csch_vals)
self.assert_function_values('csch', neg_inputs, negate(csch_vals))
# coth is odd
coth_vals = [2.164, 1.313, 1.037, 0.868 - 0.218j]
self.assert_function_values('coth', inputs, coth_vals)
self.assert_function_values('coth', neg_inputs, negate(coth_vals))
def test_hyperbolic_inverses(self):
"""
Test the inverse hyperbolic functions
which are of the form arc[X]h
"""
results = [0, 0.5, 1, 2, 1 + 1j]
sinh_vals = ['0', '0.5211', '1.1752', '3.6269', '0.635+1.2985*j']
self.assert_function_values('arcsinh', sinh_vals, results)
cosh_vals = ['1', '1.1276', '1.5431', '3.7622', '0.8337+0.9889*j']
self.assert_function_values('arccosh', cosh_vals, results)
tanh_vals = ['0', '0.4621', '0.7616', '0.964', '1.0839+0.2718*j']
self.assert_function_values('arctanh', tanh_vals, results)
sech_vals = ['1.0', '0.8868', '0.6481', '0.2658', '0.4983-0.5911*j']
self.assert_function_values('arcsech', sech_vals, results)
results = results[1:]
csch_vals = ['1.919', '0.8509', '0.2757', '0.3039-0.6215*j']
self.assert_function_values('arccsch', csch_vals, results)
coth_vals = ['2.164', '1.313', '1.0373', '0.868-0.2176*j']
self.assert_function_values('arccoth', coth_vals, results)
def test_other_functions(self):
"""
Test the non-trig functions provided in calc.py
Specifically:
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 calc.py
which are: j (complex number), e, pi, k, c, T, q
"""
# Of the form ('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):
"""
Calculate combinations of operators and default functions
"""
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)
self.assertAlmostEqual(calc.evaluator({}, {}, "sin(e)"),
0.41, delta=0.01)
self.assertAlmostEqual(calc.evaluator({}, {}, "k*T/q"),
0.025, delta=1e-3)
self.assertAlmostEqual(calc.evaluator({}, {}, "e^(j*pi)"),
-1, delta=1e-5)
def test_simple_vars(self):
"""
Substitution of variables into simple equations
"""
variables = {'x': 9.72, 'y': 7.91, 'loooooong': 6.4}
# Should not change value of constant
# even with different numbers of variables...
self.assertEqual(calc.evaluator({'x': 9.72}, {}, '13'), 13)
self.assertEqual(calc.evaluator({'x': 9.72, 'y': 7.91}, {}, '13'), 13)
self.assertEqual(calc.evaluator(variables, {}, '13'), 13)
# Easy evaluation
self.assertEqual(calc.evaluator(variables, {}, 'x'), 9.72)
self.assertEqual(calc.evaluator(variables, {}, 'y'), 7.91)
self.assertEqual(calc.evaluator(variables, {}, 'loooooong'), 6.4)
# Test a simple equation
self.assertAlmostEqual(calc.evaluator(variables, {}, '3*x-y'),
21.25, delta=0.01) # = 3 * 9.72 - 7.91
self.assertAlmostEqual(calc.evaluator(variables, {}, 'x*y'),
76.89, delta=0.01)
self.assertEqual(calc.evaluator({'x': 9.72, 'y': 7.91}, {}, "13"), 13)
self.assertEqual(calc.evaluator(variables, {}, "13"), 13)
self.assertEqual(
calc.evaluator({
'a': 2.2997471478310274, 'k': 9, 'm': 8,
'x': 0.66009498411213041},
{}, "5"),
5)
def test_variable_case_sensitivity(self):
"""
Test the case sensitivity flag and corresponding behavior
"""
self.assertEqual(
calc.evaluator({'R1': 2.0, 'R3': 4.0}, {}, "r1*r3"),
8.0)
variables = {'t': 1.0}
self.assertEqual(calc.evaluator(variables, {}, "t"), 1.0)
self.assertEqual(calc.evaluator(variables, {}, "T"), 1.0)
self.assertEqual(calc.evaluator(variables, {}, "t", cs=True), 1.0)
# Recall 'T' is a default constant, with value 298.15
self.assertAlmostEqual(calc.evaluator(variables, {}, "T", cs=True),
298, delta=0.2)
def test_simple_funcs(self):
"""
Subsitution of custom functions
"""
variables = {'x': 4.712}
functions = {'id': lambda x: x}
self.assertEqual(calc.evaluator({}, functions, 'id(2.81)'), 2.81)
self.assertEqual(calc.evaluator({}, functions, 'id(2.81)'), 2.81)
self.assertEqual(calc.evaluator(variables, functions, 'id(x)'), 4.712)
functions.update({'f': numpy.sin})
self.assertAlmostEqual(calc.evaluator(variables, functions, 'f(x)'),
-1, delta=1e-3)
def test_function_case_sensitivity(self):
"""
Test the case sensitivity of functions
"""
functions = {'f': lambda x: x,
'F': lambda x: x + 1}
# Test case insensitive evaluation
# Both evaulations should call the same function
self.assertEqual(calc.evaluator({}, functions, 'f(6)'),
calc.evaluator({}, functions, 'F(6)'))
# Test case sensitive evaluation
self.assertNotEqual(calc.evaluator({}, functions, 'f(6)', cs=True),
calc.evaluator({}, functions, 'F(6)', cs=True))
def test_undefined_vars(self):
"""
Check to see if the evaluator catches undefined variables
"""
variables = {'R1': 2.0, 'R3': 4.0}
self.assertRaises(calc.UndefinedVariable, calc.evaluator,
{}, {}, "5+7 QWSEKO")
self.assertRaises(calc.UndefinedVariable, calc.evaluator,
{'r1': 5}, {}, "r1+r2")
self.assertRaises(calc.UndefinedVariable, calc.evaluator,
variables, {}, "r1*r3", cs=True)