[issue3501] expm1 missing

Mark Dickinson <[EMAIL PROTECTED]> added the comment: I'm absorbing this issue into issue 3366. -- resolution: -> duplicate status: open -> closed superseder: -> Add gamma function, error functions and other C99 math.h functions to math module ___

[issue3501] expm1 missing

Changes by Mark Dickinson <[EMAIL PROTECTED]>: -- assignee: -> marketdickinson components: +Extension Modules -None priority: -> normal versions: +Python 2.7, Python 3.1 -Python 3.0 ___ Python tracker <[EMAIL PROTECTED]>

[issue3501] expm1 missing

Mark Dickinson <[EMAIL PROTECTED]> added the comment: A cheap trick would be to use the identity expm1(x) = 2*exp(x/2)*sinh(x/2) This could also be used in Python as a workaround, for now. But I agree that expm1 should go into the math library. ___ Python

[issue3501] expm1 missing

Mark Dickinson <[EMAIL PROTECTED]> added the comment: Mike, Can you propose an implementation, for those platforms that haven't yet caught up with C99? Something comparable to the implementation of log1p in Python/pymath.c would be appropriate. Ideally, such an implementation would: - be a

[issue3501] expm1 missing

New submission from Mike Speciner <[EMAIL PROTECTED]>: The math module contains log1p but is missing expm1 (the inverse of log1p). These functions are necessary to avoid loss of precision in floating point calculations, and are part of the C99 standard math library. -- components: None m