Is there any difference between the infinities returned by the math module and cmath module?
Does the complex infinity have an imaginary component of 0?
Add a comment |
1 Answer
Any difference?
No, there is no difference. According to the docs, both math.inf and cmath.inf are equivalent to float('inf'), or floating-point infinity.
If you want a truly complex infinity that has a real component of infinity and an imaginary component of 0, you have to build it yourself: complex(math.inf, 0)
There is, however, cmath.infj, if you want 0 as a real value and infinity as the imaginary component.
Constructing imaginary infinity
As others have pointed out math.inf + 0j is a bit faster than complex(math.inf, 0). We're talking on the order of nanoseconds though.
3 Comments
Brian61354270
Alternatively,
complex(math.inf, 0) can be constructed as math.inf + 0j or complex("inf"). Based on some back of the envelope timing with timeit, math.inf + 0j is the fastest by a noticable margin (~60 ns, versus 90 ns and 120 ns for complex("inf") and complex(math.inf, 0), respectively.)
Alec
@Brian noted in edit
Trang Oul
complex(math.inf) is enough; imaginary part is by default zero (and real too, if you use just complex()). Anyway, it'd be even better to tweak your program so it handles floats, ints (or other types) as well instead of requiring complex instances. All of the number types have imag part, equal to 0 in case of real numbers.