URL:
<http://savannah.gnu.org/bugs/?25320>
Summary: Import fresnel, bugs on GSL Extension Fresnel
Project: GNU Scientific Library
Submitted by: bjg
Submitted on: Wed 14 Jan 2009 05:41:30 PM GMT
Category: Accuracy problem
Severity: 3 - Normal
Уеб-?траница:
Status: None
Assigned to: None
Open/Closed: Open
Release: 1.12
Discussion Lock: Any
_______________________________________________________
Details:
The fresnel extension should be imported for the next release, with the
following bug report checked.
From: "Toshiro Ohsaki" <[email protected]>
To: <[email protected]>
Subject: [Bug-gsl] Bugs on GSL Extension Fresnel
Date: Wed, 26 Nov 2008 21:07:02 +0900
Dear staff of GNU
I found bugs on GSL Extensions/Applications Fresnel by Andrew Steiner.
This program does not return a correct value, if x is negative.
The original function fresnel_c is coded as,
double fresnel_c(double x)
{
double xx = x*x*pi_2;
double ret_val;
if(xx<=8.0)
ret_val = fresnel_cos_0_8(xx);
else
ret_val = fresnel_cos_8_inf(xx);
return (x<0.0) ? -ret_val : ret_val;
}
.
I think it should be coded as,
double fresnel_c(double x)
{
double xx = x*x*pi_2;
double ret_val;
double sign;
if(xx < 0.0){
xx*=-1.0;
sign=-1.0;
}
else{
sign=1.0;
}
if(xx<=8.0)
ret_val = fresnel_cos_0_8(xx);
else
ret_val = fresnel_cos_8_inf(xx);
ret_val*=sign;
return(ret_val);
}
.
The same correction should be done on the function fresnel_s.
Sincerely yours,
Toshiro Ohsaki
from Tokyo Japan.
_______________________________________________
Bug-gsl mailing list
[email protected]
http://lists.gnu.org/mailman/listinfo/bug-gsl
_______________________________________________________
Reply to this item at:
<http://savannah.gnu.org/bugs/?25320>
_______________________________________________
Message sent via/by Savannah
http://savannah.gnu.org/
_______________________________________________
Bug-gsl mailing list
[email protected]
http://lists.gnu.org/mailman/listinfo/bug-gsl
