Hi
I am using Petsc solve ODE nonlinear problem. I was told to use direct method: umfpackage because of the jacobian matrix is 1860 by 1860. But the time consumption is still too big: TSSetType(ts,TSBEULER) time ./pihm -log_summary -ksp_type preonly -pc_type lu -pc_factor_mat_solver_package umfpack I got the result: -------------- next part -------------- A non-text attachment was scrubbed... Name: Screen shot 2010-10-21 at 5.41.41 PM.png Type: image/png Size: 126875 bytes Desc: not available URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20101021/3aed5e32/attachment-0002.png> -------------- next part -------------- When I use TSSetType(ts,TSSUNDIALS), it is fast: -------------- next part -------------- A non-text attachment was scrubbed... Name: Screen shot 2010-10-21 at 5.41.54 PM.png Type: image/png Size: 40592 bytes Desc: not available URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20101021/3aed5e32/attachment-0003.png> -------------- next part -------------- How can I find the reason why BEULER is so slow? Thanks Xuan
