What you are looking for is the first one.

Right.

I see this is automatically set. I don't see this initialization in petsc - so perhaps the compiler is doing this automatically? [atleast by gfortran]

Our code initialized PETSC objects to "NULL". I was thinking that we should remove this, like ex73f90t. But, yea, if the compiler initializes this to 0 (PETSC_NULL_VEC) then we are broken again. It looks like ex73f90t would fail if the compiler initialized the members of our Fortran types to 0 ...

Satish

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Breakpoint 2, MAIN__ () at ex1f.F90:51 51 x = PETSC_NULL_VEC (gdb) list 33 28 ! 29 Vec x,b,u 30 Mat A 31 KSP ksp 32 PC pc 33 PetscReal norm,tol 34 PetscErrorCode ierr 35 PetscInt i,n,col(3),its,i1,i2,i3 36 PetscBool flg 37 PetscMPIInt size (gdb) p x $2 = ( v = -2 ) (gdb) p b $3 = ( v = -2 ) (gdb) p u $4 = ( v = -2 ) (gdb) p A $5 = ( v = -2 ) (gdb) p ksp $6 = ( v = -2 ) (gdb) p pc $7 = ( v = -2 ) (gdb) c Continuing.

Breakpoint 3, MAIN__ () at ex1f.F90:52 52 call MPI_Comm_size(PETSC_COMM_WORLD,size,ierr) (gdb) p x $8 = ( v = 0 ) (gdb)

On Tue, 17 Mar 2020, Mark Adams wrote:

...

...

Passing NULL to MatCreateVecs() means that you do not want a vector

out:

...

Yes, I want both vectors out and we pass it Vec that have been initialized with PETSC_NULL_VEC

...

https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Mat/MatCreateVe...

...

I am guessing that this was broken in 3.7 so that it ignored NULL

input,

...

but we fixed that.

v3.7 has these CHKFORTRANNULLOBJECT. Well the "fix" broke working code

ex73f90t does not initialize the "x" vector that it gives to matcreatevecs_. Should we just remove initialization of our vectors to PETSC_NUILL_VEC?

Is the PETSc model that you don't inialized PETSc object to NULL because you check that pointers are valid PETSc pointers instead of testing on NULL? So maybe we should remove all these initializations.

Thanks, Mark

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Thanks,

Matt

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call MatCreateVecs(solver%KKTmat,solver%xVec2,solver%bVec2,ierr)

Petsc code: PETSC_EXTERN void PETSC_STDCALL matcreatevecs_(Mat *mat,Vec *right,Vec *left, int *ierr) { PetscPrintf(PETSC_COMM_SELF,"ZZZ 1) matcreatevecs_ start right=%p left=%p\n",right,left); CHKFORTRANNULLOBJECT(right); CHKFORTRANNULLOBJECT(left); PetscPrintf(PETSC_COMM_SELF,"ZZZ 2) matcreatevecs_ start right=%p left=%p\n",right,left); *ierr = MatCreateVecs(*mat,right,left); }

produces this:

ZZZ 1) matcreatevecs_ start right=0x7fffffff3758 left=0x7fffffff3760 ZZZ 2) matcreatevecs_ start right=(nil) left=(nil)

Shouldn't this be?

PETSC_EXTERN void PETSC_STDCALL matcreatevecs_(Mat *mat,Vec *right,Vec *left, int *ierr) { *ierr = MatCreateVecs(*mat,right,left); }

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