Re: [petsc-users] Problem with TS and SNES VI

2019-09-02 Thread Constantinescu, Emil M. via petsc-users
Moritz, If you use ARKIMEX(3,4,5) and force the time step to be small [try setting -ts_dt_max] - do you still get negatives? If you are not, it may be due to the time steps being too large relative to the dynamics of your system, forcing it in the negative territory. This is typical when one

[petsc-users] is TS_EQ_DAE_SEMI_EXPLICIT_INDEX functional

2019-09-02 Thread Huck, Moritz via petsc-users
Hi, TS_EQ_DAE_SEMI_EXPLICIT_INDEX(?) are defined in TSEquationType but not mentioned in the manual. Is this feature functional ? If yes how do I have to define the RHSFunction? (I am asking since the ODE variant has it defined as G= M^-1 g, which cannot work for a DAE) Best Regards, Moritz

[petsc-users] Handling infeasible solution iterates in TS/SNES

2019-09-02 Thread Steve via petsc-users
Hello, I have another beginner's PETSc question.  Apologies if the solution is obvious, but I've looked around the manual and the API and haven't yet spotted a solution. I'm solving a nonlinear problem using the BDF TSP (although the same issue arises if I use BEULER and other TS - it's not

Re: [petsc-users] Handling infeasible solution iterates in TS/SNES

2019-09-02 Thread Smith, Barry F. via petsc-users
Steve, There are two levels at which "out of domain" (infeasible) errors can/should be indicated: 1) First call TSSetFunctionDomainError(). TS calls your provided function when candidate solutions are generated, if the new solution is not feasible, as indicated by this

Re: [petsc-users] is TS_EQ_DAE_SEMI_EXPLICIT_INDEX functional

2019-09-02 Thread Jed Brown via petsc-users
I believe this is intended to work with most any implicit solver, *provided* the initial conditions are compatible. It was added by Emil, but I don't see it explicitly tested in PETSc. "Huck, Moritz via petsc-users" writes: > Hi, > TS_EQ_DAE_SEMI_EXPLICIT_INDEX(?) are defined in TSEquationType

[petsc-users] Error in creating compressed data using HDF5

2019-09-02 Thread Danyang Su via petsc-users
Dear All, Not sure if this is the right place to ask hdf5 question. I installed hdf5 through PETSc configuration --download-hdf5=yes. The code runs without problem except the function to create compressed data (red part shown below).     !c create local memory space and hyperslab     call

Re: [petsc-users] Error in creating compressed data using HDF5

2019-09-02 Thread Smith, Barry F. via petsc-users
You could try the master branch of PETSc that uses a much more recent branch of hdf5 When you did the --download-hdf5 did you also do --download-zlib and --download-szlib (though I would hope hdf5 would give you a very useful error message that they need to be installed instead of the