Added math module (#33)

lib/math.py

+# Copyright 2016 Google Inc. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __go__.math import (Pi, E, Ceil, Copysign, Abs, Floor, Mod, Frexp, IsInf,
+    IsNaN, Exp2, Modf, Trunc, Exp, Expm1, Log, Log1p, Log10, Pow, Sqrt, Acos,
+    Asin, Atan, Atan2, Hypot, Sin, Cos, Tan, Acosh, Asinh, Atanh, Sinh, Cosh,
+    Tanh, Erf, Erfc, Gamma, Lgamma) # pylint: disable=g-multiple-import
+
+# Constants
+
+pi = Pi
+
+
+e = E
+
+
+# Number-theoretic and representation functions
+
+def ceil(x):
+    return Ceil(float(x))
+    
+    
+def copysign(x, y):
+    return Copysign(float(x), float(y))
+
+    
+def fabs(x):
+    return Abs(float(x))
+
+
+def factorial(x):
+    try:
+        xi = int(x)
+    except TypeError:
+        xi = None
+    
+    try:
+        xf = float(x)
+    except TypeError:
+        xf = None
+    
+    if xi is None:
+        xi = int(xf)
+        if xi != xf:
+            raise ValueError("factorial() only accepts integral values")
+    elif xf is None and xi is None:
+        raise TypeError("an integer is required")
+    elif xf is None:
+        pass
+    elif xf != xi:
+        raise ValueError("factorial() only accepts integral values")
+    
+    x = xi
+    
+    if x < 0:
+        raise ValueError("factorial() not defined for negative values")
+    
+    acc = 1
+    
+    for value in range(2,x+1):
+        acc *= value
+    
+    return acc
+
+
+def floor(x):
+    return Floor(float(x))
+
+
+def fmod(x):
+    return Mod(float(x))
+
+
+def frexp(x):
+    return Frexp(float(x))
+
+
+# TODO: Implement fsum()
+# def fsum(x):
+#    pass
+
+
+def isinf(x):
+    return IsInf(float(x),0)
+    
+    
+def isnan(x):
+    return IsNaN(float(x))
+
+
+def ldexp(x, i):
+    return float(x) * Exp2(float(i))
+    
+    
+def modf(x):
+    #Modf returns (int, frac), but python should return (frac, int).
+    a, b = Modf(float(x))
+    return b, a
+
+    
+def trunc(x):
+    return Trunc(float(x))
+
+
+# Power and logarithmic functions
+
+def exp(x):
+    return Exp(float(x))
+
+
+def expm1(x):
+    return Expm1(float(x))
+
+
+def log(x, b=None):
+    if b is None:
+        return Log(float(x))
+
+    # NOTE: We can try and catch more special cases to delegate to specific
+    # Go functions or maybe there is a function that does this and I missed it.
+    return Log(float(x)) / Log(float(b))
+
+
+def log1p(x):
+    return Log1p(float(x))
+    
+    
+def log10(x):
+    return Log10(float(x))
+    
+    
+def pow(x, y):
+    return Pow(float(x), float(y))
+
+
+def sqrt(x):
+    return Sqrt(float(x))
+
+
+# Trigonometric functions
+
+def acos(x):
+    return Acos(float(x))
+
+
+def asin(x):
+    return Asin(float(x))
+
+
+def atan(x):
+    return Atan(float(x))
+
+
+def atan2(y, x):
+    return Atan2(float(y), float(x))
+    
+    
+def cos(x):
+    return Cos(float(x))
+
+
+def hypot(x, y):
+    return Hypot(float(x), float(y))
+
+
+def sin(x):
+    return Sin(float(x))
+
+
+def tan(x):
+    return Tan(float(x))
+
+
+# Angular conversion
+
+def degrees(x):
+    return (float(x) * 180) / pi
+
+
+def radians(x):
+    return (float(x) * pi) / 180
+
+
+# Hyperbolic functions
+
+def acosh(x):
+    return Acosh(float(x))
+    
+    
+def asinh(x):
+    return Asinh(float(x))
+    
+    
+def atanh(x):
+    return Atanh(float(x))
+
+
+def cosh(x):
+    return Cosh(float(x))
+
+
+def sinh(x):
+    return Sinh(float(x))
+    
+    
+def tanh(x):
+    return Tanh(float(x))
+    
+    
+# Special functions
+
+def erf(x):
+    return Erf(float(x))
+    
+    
+def erfc(x):
+    return Erfc(float(x))
+
+
+def gamma(x):
+    return Gamma(float(x))
+    
+    
+def lgamma(x):
+    return Lgamma(float(x))

lib/math_test.py

+# Copyright 2016 Google Inc. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import math
+
+import weetest
+
+# Tests exist for all functions which have logic in the math.py module, instead
+# of simply calling the go equivalent.
+
+
+def TestFactorial():
+  assert math.factorial(0) == 1
+  assert math.factorial(1) == 1
+  assert math.factorial(2) == 2
+  assert math.factorial(3) == 6
+  assert math.factorial(4) == 24
+  assert math.factorial(5) == 120
+
+
+def TestFactorialError():
+  try:
+    math.factorial(-1)
+  except ValueError:
+    pass
+  else:
+    raise AssertionError
+  
+  try:
+    math.factorial(0.5)
+  except ValueError:
+    pass
+  else:
+    raise AssertionError
+
+
+def TestLdexp():
+  assert math.ldexp(1,1) == 2
+  assert math.ldexp(1,2) == 4
+  assert math.ldexp(1.5,1) == 3
+  assert math.ldexp(1.5,2) == 6
+
+
+def TestLog():
+  assert math.log(math.e) == 1
+  assert math.log(2,2) == 1
+  assert math.log(10,10) == 1
+  assert math.log(100,10) == 2
+
+
+def TestRadians():
+  assert math.radians(180) == math.pi
+  assert math.radians(360) == 2 * math.pi
+
+
+def TestDegrees():
+  assert math.degrees(math.pi) == 180
+  assert math.degrees(2 * math.pi) == 360
+
+
+if __name__ == '__main__':
+  weetest.RunTests()