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classification
Title: Complex division is braindead
Type: Stage:
Components: Interpreter Core Versions:
process
Status: closed Resolution: fixed
Dependencies: Superseder:
Assigned To: tim.peters Nosy List: tim.peters
Priority: normal Keywords:

Created on 2001-03-17 21:45 by tim.peters, last changed 2022-04-10 16:03 by admin. This issue is now closed.

Messages (2)
msg3946 - (view) Author: Tim Peters (tim.peters) * (Python committer) Date: 2001-03-17 21:45 
>>> x = complex(1e200, 1e200)
>>> x/x
0j
>>> x = complex(1e-200, 1e-200)
>>> x/x
(1.#INF-1.#INDj)
>>> 

This is nothing new; it's always been this way; the 
algorithm we use is numerically naive, ignoring the 
possibility for overflow and underflow in internal 
intermediate results.  The results will vary across 
platforms in such cases, in unpredictable ways (the 
above was run on a WinTel box).
msg3947 - (view) Author: Tim Peters (tim.peters) * (Python committer) Date: 2001-03-18 08:24 
Logged In: YES 
user_id=31435

Now less braindead.

Lib/test/test_complex.py: initial revision: 1.1
Lib/test/output/test_complex: initial revision: 1.1
Objects/complexobject.c: new revision: 2.35
History
Date User Action Args
2022-04-10 16:03:52adminsetgithub: 34183
2001-03-17 21:45:09tim.peterscreate