Added note about Python's support of complex numbers.

Added exp(z).
This commit is contained in:
Guido van Rossum 1996-07-30 19:02:01 +00:00
parent 89cb67bb64
commit 72ba616066

View File

@ -1,6 +1,9 @@
# Complex numbers
# ---------------
# [Now that Python has a complex data type built-in, this is not very
# useful, but it's still a nice example class]
# This module represents complex numbers as instances of the class Complex.
# A Complex instance z has two data attribues, z.re (the real part) and z.im
# (the imaginary part). In fact, z.re and z.im can have any value -- all
@ -15,6 +18,7 @@
# PolarToComplex([r [,phi [,fullcircle]]]) ->
# the complex number z for which r == z.radius() and phi == z.angle(fullcircle)
# (r and phi default to 0)
# exp(z) -> returns the complex exponential of z. Equivalent to pow(math.e,z).
#
# Complex numbers have the following methods:
# z.abs() -> absolute value of z
@ -202,7 +206,9 @@ class Complex:
if z is not None:
raise TypeError, 'Complex does not support ternary pow()'
if IsComplex(n):
if n.im: raise TypeError, 'Complex to the Complex power'
if n.im:
if self.im: raise TypeError, 'Complex to the Complex power'
else: return exp(math.log(self.re)*n)
n = n.re
r = pow(self.abs(), n)
phi = n*self.angle()
@ -211,6 +217,10 @@ class Complex:
def __rpow__(self, base):
base = ToComplex(base)
return pow(base, self)
def exp(z):
r = math.exp(z.re)
return Complex(math.cos(z.im)*r,math.sin(z.im)*r)
def checkop(expr, a, b, value, fuzz = 1e-6):