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IEEE special values

Hi there,

is there any simple reason why IEEE special values are so poorly supported
in python? Are there any serious efforts to change that? NaN and Inf are an
extremely useful concept for numerical calculations and they would mix
perfectly with the concepts in NumPy, anyhow, the support seems to be
absolutely minimal.

(The ideas in PEP 754 do not really change much: There is little use in easy
access to those values, if the math functions don't accept them as input
but break down.)

Ciao,
Nobbi
Jul 18 '05 #1
2 1910

"Norbert Nemec" <no**************************************@NOSPAM.C OM> wrote
in message news:bh**********@rznews2.rrze.uni-erlangen.de...
Hi there,

is there any simple reason why IEEE special values are so poorly supported
in python? Are there any serious efforts to change that? NaN and Inf are an extremely useful concept for numerical calculations and they would mix
perfectly with the concepts in NumPy, anyhow, the support seems to be
absolutely minimal.

(The ideas in PEP 754 do not really change much: There is little use in easy access to those values, if the math functions don't accept them as input
but break down.)
Like a lot of things, Python's math functions are a rather thin layer
on top of the native C library's math functions. If the C library's
math functions, to use the vernacular, suck, then Python's math
functions will do likewise.

One of the essential problems is that every library does certain
things differently, like deciding whether it's going to start up with
silent or signaling NaN's, or what the actual string values are for
NaN, infinity and so forth.

It takes developer time to clean up that situation. I suspect
that volunteers would be very welcome.

John Roth

Ciao,
Nobbi

Jul 18 '05 #2

"Norbert Nemec" <no**************************************@NOSPAM.C OM>
wrote in message news:bh**********@rznews2.rrze.uni-erlangen.de...
is there any simple reason why IEEE special values are so poorly supported in python?


A. They are poorly, and just as importantly, inconsistently supported
in C.
B. Python's floating point arithmetic and standard functions are thin
wrappers of the C layer.

TJR
Jul 18 '05 #3

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