[petsc-users] Check if allocated in Fortran

[Satish Balay]

Perhaps the following code?

      Vec              x

      x = PETSC_NULL_VEC
      if (x .eq. PETSC_NULL_VEC) then
         print*,'vec is null'
      endif

Satish

On Mon, 26 Feb 2018, Sanjay Govindjee wrote:

> I am trying to update some code that works in version 3.7.6 to version 3.8.3.
> 
> What is the recommended way to check if a petsc type, such as Vec, has already
> been created?
> 
> Current code looks like:
> 
> Vec xvec
> 
> if(xvec.eq.0) then          ! Check if xvec needs to be created
>   call VecCreate(PETSC_COMM_WORLD, xvec, ierr)
> endif
> 
> In PETSc 3.8.3 I am now getting a compiler error
> 
> parkv.F(60): error #6355: This binary operation is invalid for this data
> type.   [XVEC]
>       if(xvec.eq.0) then
> ---------^
> 
>