Re: GSL function problem

[Allin Cottrell <cottrell wfu edu>]

On Thu, 13 Jul 2006, laurency franck wrote:

> i have created a plugin for gnumeric and i want to add it some 
> other functions. These functions use GSL function: 
> "gsl_interp_cspline". So i have included files 
> "gsl/gsl_errno.h" and "gsl/gsl_spline.h" . But when i try to 
> use my plugin there is this error which appeared:
>
> E/pc85/home/laurency/softs//lib/gnumeric/1.7.1/plugins/fn-TimeSeriesAnalysis 
> /plugin.so: undefined symbol: gsl_interp_cspline
>
> And i don't understand why "gsl_interp_cspline" is not defined 
> as i have included file "gsl/gsl_spline.h"

By including the relevant header you, in effect, assure your 
plugin code that there is such a symbol, somewhere.  But unless 
the symbol is a trivial macro it's not actually defined yet, 
merely declared.  You've said, "Trust me, I'm going to provide 
gsl_interp_cspline, which takes such-and-such arguments and 
returns such-and-such a value."  But to make good on your 
promise, you have to link to the library that actually defines 
(provides) that function, -L/somedir -lgsl.

Allin Cottrell