GNU Scientific Library  Bugs: bug #58064, Inconsistent evaluation of limits...
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bug #58064: Inconsistent evaluation of limits in special functions
Submitter:  Jackson Vanover <jacksonvanover>  
Submitted:  Sat 28 Mar 2020 05:20:50 PM UTC  
Category:  Accuracy problem  Severity:  3  Normal 
Operating System:  18.04  Status:  None 
Assigned to:  None  Open/Closed:  Open 
Release:  2.6 
Fri 29 May 2020 02:11:34 AM UTC, comment #1: 
Jackson Vanover <jacksonvanover> 
Sat 28 Mar 2020 05:20:50 PM UTC, original submission:
Using version 2.6 of GSL from ftp://ftp.gnu.org/gnu/gsl/gsl2.6.tar.gz
OS is Ubuntu 18.04.2 LTS
Hardware is a Dell workstation with a 3.60 GHz Intel i74790 and 32 GB
Compiler is gcc 7.4.0 with the w option
All of the below pertain to evaluation of limits; I bring these
 When the first argument is infinity, gsl_sf_gamma_inc_Q consistently
 When evaluating gsl_sf_gamma_inc_Q(x, inf) where x is some floating point
 When evaluating gsl_sf_erf(inf), a NaN is returned even though the limit
 When evaluating gsl_sf_gamma_inc(x, inf) where x is some floating point
 When the first argument is infinity, gsl_sf_gamma_inc_P consistently
 When evaluating gsl_sf_gamma_inc_P(x, inf) where x is some floating point
 When the first argument to gsl_sf_poch is a negative
 When evaluating the Si(inf), we get a return of NaN though the limit

Jackson Vanover <jacksonvanover> 
No files currently attached
Depends on the following items: None found
Items that depend on this one: None found
An additional case:
 When evaluating gsl_sf_erfc(inf), a NaN is returned even though the limit
approaches 0, e.g. gsl_sf_erfc(GSL_POSINF)