From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian Gough To: redonnetNO@SPAMlgmt.ups-tlse.fr Cc: gsl-discuss@sourceware.cygnus.com Subject: Re: Some (probably) ridiculous questions Date: Wed, 19 Dec 2001 13:20:00 -0000 Message-id: <15173.56028.740003.364874@debian> References: <01070611531200.01910@lgmt-fab5.ups-tlse.fr> X-SW-Source: 2001/msg00270.html Jean-Max Redonnet writes: > Sorry, if this point is obvious, but I'm not very familiar with GSL and I > would like to use it in the right way. > > My question is : How to declare a function of multiple variables ? > > I manage with parametric curves and surfaces, so I need functions of one or > two parameters. Futhermore This functions should be vectorial. > For example : I need to deal with a ruled surface. Hello, The gsl_function type is mainly designed for interfacing to the univariate gsl routines. It is not really a general facility so it does not handle other cases that are not used in the library, such as surfaces. The way to handle this sort of situation is, -- define your own surface function type in the way that you normally would in your C-programs -- if you need to use a gsl routine, for example to integrate along a line, define a function to create the appropriate gsl_function by mapping from your surface type. Philosophically, calls to GSL routines, and the GSL types, can be at a "lower-level" than your program. regards Brian Gough