Re: ODE's again (sorry)

[Slaven Peles <peles at cns dot physics dot gatech dot edu>]

On Saturday 02 March 2002 11:26 am, Sam Halliday wrote:
> hello all,
>
> i have been having problems with the ODE's of gsl 1.1. i thought i had it
> mastered when i solved lane-emden (which is not disimilar to the
> thomas-fermi equation), but now i have moved onto solving 3 simple
> newtonian motion equations, which need to have solutions from the other in
> order to calculate the next value...
>
> so i tried making 3 calls to the runge-kutta (4th order), which worked for
> me before, and if i solve for one of these 3 equations by itself, it seems
> to work, however if i change the step range in my solution to only solve
> for 1 value (instead of a whole range), i get a slight error in the 2nd
> calculated values with respect to the solution over a range, here is some
> sample data
> --solution by one call to my function (similar to the fixed-step example in
> the docs), solving for the whole range:
>

Hi,

It's not quite clear to me what are you trying to do. Could you explain in a 
greater detail what calculation you are doing and perhaps send relevant 
pieces of code? 

Cheers,
Slaven