URL:
<http://savannah.gnu.org/bugs/?33679>
Summary: gsl_sf_mathieu_se_array calculates zeroth se as
non-zero value
Project: GNU Scientific Library
Submitted by: nikolays
Submitted on: Thu 30 Jun 2011 11:20:43 AM GMT
Category: Runtime error
Severity: 3 - Normal
Operating System: Gentoo 10.0 amd64
Status: None
Assigned to: None
Open/Closed: Open
Release:
Discussion Lock: Any
_______________________________________________________
Details:
It is well known, that eigenvalue *b0* for the odd solution b0 is not exist
<http://dlmf.nist.gov/28.2#F1>. Therefore the zeroth odd Mathieu function se
is equal to zero.
In gsl_sf_mathieu_se you have check for trivial case where order=0. But there
is no such check in gsl_sf_mathieu_se_array.
So _gsl_sf_mathieu_se_array_ calculates se0 as non-zero.
I can illustrate my thoughts with simple example (gsl_se_test.c).
It calculates *se* functions for orders 0 and 1 with values of q=-10,0,10. The
program calculates values with _gsl_sf_mathieu_se_ and
_gsl_sf_mathieu_se_array_. As you can see se0 values from array does not equal
to zero:
q = -10.0
se_0 = 0.0000000000
se_0 = 0.6115006542 (from array)
q = 10.0
se_0 = 0.0000000000
se_0 = 0.6115006542 (from array)
P.S. I use GSL 1.15.
_______________________________________________________
File Attachments:
-------------------------------------------------------
Date: Thu 30 Jun 2011 11:20:43 AM GMT Name: gsl_se_test.c Size: 865B By:
nikolays
gsl_sf_mathieu_se_array and gsl_sf_mathieu_se test program
<http://savannah.gnu.org/bugs/download.php?file_id=23592>
_______________________________________________________
Reply to this item at:
<http://savannah.gnu.org/bugs/?33679>
_______________________________________________
Message sent via/by Savannah
http://savannah.gnu.org/
_______________________________________________
Bug-gsl mailing list
[email protected]
https://lists.gnu.org/mailman/listinfo/bug-gsl
