periodic gsl_spline problem

periodic gsl_spline problem

[Simon Ching]

Hello

I have a problem working with gsl_spline
with interpolation type cspline_periodic
and I am not sure if this is a bug.

Attached is a graphics showing 3 interpolation
curves from the control points shown as big
red circles.  The red, green and blue lines
are from the results using cspline_periodic,
cspline and linear interpolation types
respectively.

What caught my attention is that the red curve
does not go back to (2*pi, 0).

What should be the workaround? Should I specify
9 points (including the redundant end point) for
cspline_peridic, too, instead?  The would be
a little bit weird because that point is
really redundant.

I would be grateful if someone can shed some
light on me on this issue. Thank you very
much, and keep up the good work on GSL! I use
GSL everyday! :) 

Regards,
Simon.

=====
Simon E Ching
-----------------------------------------------------------
                               email: simon_ching@yahoo.com
                      http://www.geocities.com/simon_ching/

_______________________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com.hk address at http://mail.english.yahoo.com.hk

Re: periodic gsl_spline problem

[Brian Gough]

Simon Ching writes: 
 > I have a problem working with gsl_spline with interpolation type
 > cspline_periodic and I am not sure if this is a bug.
 > 
 > What caught my attention is that the red curve
 > does not go back to (2*pi, 0).

Could you submit a bug report to bug-gsl@gnu.org with an
example program that reproduces the behavior -- thanks.

-- 
Brian Gough

Network Theory Ltd,
Commercial support for GSL --- http://www.network-theory.co.uk/gsl/

periodic gsl_spline problem

[Simon Ching]

[-- Attachment #1: Type: text/plain, Size: 424 bytes --]

Hello,

Whoops, I forgot to attach the png! :P

Regards,
Simon.

=====
Simon E Ching
-----------------------------------------------------------
                               email: simon_ching@yahoo.com
                      http://www.geocities.com/simon_ching/

_______________________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com.hk address at http://mail.english.yahoo.com.hk

[-- Attachment #2: gsl_spline.png --]
[-- Type: image/png, Size: 34454 bytes --]