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Levi April 6, 2003 08:35

Need ODE solver
 
Hi all, I am looking for an ODE solver for large systems (maybe stiff). The number of ordinary diff. equations is ~ 10^6. For solving we have a parallel cluster with 64 CPU. Does anyone know where to find such code? Thanks in advance.

Manan April 7, 2003 14:02

Re: Need ODE solver
 
Hi Levi

If you are working in fortran then u can use lsoda.f available on net. It employs Gears adaptive time step method used for stiff odes. Although C versions of the code is also available,I am not sure about its implementation.

Manan

Levi April 9, 2003 08:37

Re: Need ODE solver
 
Thank you, Manan. I know lsoda.f, lsode.f, etc codes and I use its for a long time. But all such codes are aimed at full matrixes. They contain long working arrays (~ 2*N^2). If N~10^6 it is obviously that there are not enough memory. I've very sparse matrix when only 7 elements from a million are non-zero in the each line. Are there any special solvers for such case?


Manan April 9, 2003 22:38

Re: Need ODE solver
 
Hi Levi,

lsoda solved my problem so i didnt look anywhere else.I know a group working in my deptt which uses ode solvers and are abreast with latest development in this field. If you want the contact just mail me and I can send it to u.

Manan


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