[petsc-users] DMDACoor3d and VecView

[Jed Brown]

Roc Wang <pengxwang at hotmail.com> writes:

>  Thanks, I followed the src/dm/examples/tests/ex14.c and ex13.c. There is still
> error. Please take a look at the followings:

>  //The portion of writing vector in Solver program
>  /* write da, solution Vec Coordinate Da and Vec cda in binary format */
>   ierr = PetscLogEventRegister("Generate Vector",VEC_CLASSID,&VECTOR_WRITE);
> CHKERRQ(ierr);
>   ierr = PetscLogEventBegin(VECTOR_WRITE,0,0,0,0);CHKERRQ(ierr);
>   ierr = PetscPrintf(PETSC_COMM_WORLD,"writing vector in binary to vector.bin
> ...\n");CHKERRQ(ierr);
>   ierr = PetscViewerBinaryOpen(PETSC_COMM_WORLD,"vector.bin",FILE_MODE_WRITE,&
> viewer);CHKERRQ(ierr);
  
>   ierr = DMView(da,viewer);CHKERRQ(ierr);
>   ierr = VecView(x,viewer);CHKERRQ(ierr);

>   ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
>   ierr = PetscLogEventEnd(VECTOR_WRITE,0,0,0,0);CHKERRQ(ierr);   

> //The portion of reading vector in the post-processing program
> /* Read new vector in binary format */
>   DM da;
>   Vec uu;
 
>  ierr = PetscLogEventRegister("Read Vector",VEC_CLASSID,&VECTOR_READ);CHKERRQ
> (ierr);
>   ierr = PetscLogEventBegin(VECTOR_READ,0,0,0,0);CHKERRQ(ierr);
>   ierr = PetscPrintf(PETSC_COMM_WORLD,"reading vector in binary from vector.bin
> ...\n");CHKERRQ(ierr);
>   ierr = PetscViewerBinaryOpen(PETSC_COMM_WORLD,"vector.bin",FILE_MODE_READ,&
> viewer);CHKERRQ(ierr);

>   //ierr = DMCreate(PETSC_COMM_WORLD,&da);CHKERRQ(ierr);   //NOTE A

>   ierr = DMLoad(da,viewer);CHKERRQ(ierr);
>   ierr = DMCreateGlobalVector(da,&uu);CHKERRQ(ierr);
 
>   ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
>   ierr = PetscLogEventEnd(VECTOR_READ,0,0,0,0);CHKERRQ(ierr);

> If  the line of  ierr = DMCreate(PETSC_COMM_WORLD,&da);CHKERRQ(ierr);  //NOTE A
>  is commented out,   the error is like:
> [2]PETSC ERROR: --------------------- Error Message
> ------------------------------------
> [2]PETSC ERROR: Invalid argument!
> [2]PETSC ERROR: Wrong type of object: Parameter # 1!
> [2]PETSC ERROR:
> ------------------------------------------------------------------------

1. ALWAYS paste the entire error message.

2. This is a memory error.

> If  with ierr = DMCreate(PETSC_COMM_WORLD,&da);CHKERRQ(ierr);   //NOTE A, the
> error is like:
> [0]PETSC ERROR: --------------------- Error Message
> ------------------------------------
> [0]PETSC ERROR: Arguments are incompatible!
> [0]PETSC ERROR: Cannot change block size 3 to 1!
> [0]PETSC ERROR:
> ------------------------------------------------------------------------

Use VecSetOptionsPrefix(gc,"coord_") in both the code that writes and
the code that reads, before VecView and VecLoad respectively.


The simple PETSc binary format cannot distinguish the options unless you
set different prefixes.