[petsc-users] SNESSetOptionsPrefix usage

[Smith, Barry F.]

  Should still work. Run in the debugger and put a break point in snessetoptionsprefix_ and see what it is trying to do

  Barry


> On Jan 15, 2020, at 8:58 AM, Timothée Nicolas <timothee.nicolas at gmail.com> wrote:
> 
> Hi, thanks for your answer,
> 
> I'm using Petsc version 3.10.4
> 
> Timothée
> 
> Le mer. 15 janv. 2020 à 14:59, Mark Adams <mfadams at lbl.gov> a écrit :
> I'm guessing a Fortran issue. What version of PETSc are you using?
> 
> On Wed, Jan 15, 2020 at 8:36 AM Timothée Nicolas <timothee.nicolas at gmail.com> wrote:
> Dear PETSc users,
> 
> I am confused by the usage of SNESSetOptionsPrefix. I understand this is required if you have for example different SNES in your program and want to set different options for them.
> So for my second snes I wrote 
> 
> call SNESCreate(MPI_COMM_SELF,snes,ierr)
> call SNESSetOptionsPrefix(snes,'green_',ierr)
> call SNESSetFromOptions(snes,ierr)
> 
> etc.
> 
> Then when launching the program I wanted to monitor that snes so I launched it with the option -green_snes_monitor instead of -snes_monitor. But I keep getting the message
> 
> WARNING! There are options you set that were not used!
> WARNING! could be spelling mistake, etc!
> Option left: name:-green_snes_monitor (no value)
> 
> What do I miss here?
> 
> Best regards
> 
> Timothée NICOLAS