[SciPy-User] Integrating large ODE problems with sundials.

[Peter John Garrone]

Hi,
 Some time ago I wrote that I was having problems with ODE algorithm solving, where most of the time appeared to be lost in the algorithm.

 In fact the problem appears to be within the PySUNDIALS implementation that I downloaded from sourceforge, pysundials-2.3.0-rc2. When I implemented my own simple interface, in fact only about five percent of the cpu time is spent within the algorithm. My approximate times for a 100000 state problem were:

 dydt/right-hand side equation:  20 percent
 Jacobian and sparse matrix creation: 35 percent
 Preconditioner sparse solve: 40 percent
 Remainder, including algorithm: 5 percent

With the pysundials implementation, the remainder portion would have been about 95 percent, with the other categories adding up to about 4 percent.
 So I do conclude there is something poor about the pysundials implementation, possibly the N_Vector implementation, for big problems, using standard python.

Cheers,