ODEPACK

[ushomirs(at)my-deja.com]

Hi,

It looks like IDL 5.2 includes one of the ODEPACK routines, LSODE. But
that's just the basic routine, FORTRAN ODEPACK on Netlib (which is where
i think they got the routine) has several more sophisticated routines.

In addition, it seems that RSI has done a sloppy job integrating LSODE
into IDL.  they don't support all the options the original LSODE has,
including the useful ones, like single-stepping through the integration.
the documentation seems haphazardly put together.  for example, their
description of output value STATUS=3 is

"The integration was performed successfully, and no roots were found"

what roots?? anyway, this makes me doubt the correctness of the
implementation.

Anyway, I have 2 questions.
(1) does anyone know if RSI has plans to integrate the rest of ODEPACK
routines into IDL??

(2) Since the answer to (1) is probably "No", how do I call an IDL
routine from a DLM (dynamically loadable module)??  What i'm thinking is
just compiling all of the odepack routines into a dlm, and writing and
IDL interface.  however, i would need to pass the function that computes
the right-hand side of the differential equation to the FORTRAN routine
in a dlm. IDL external development guide describes how to call external
routines from IDL, but not the other way around.

Please note that "Callable IDL"  is probably **not** what's needed here.
It seems to me that "callable idl"  inits a whole separate copy of idl,
which is clearly not what i need here.  (unless i'm wrong on this
point).


greg


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