PETSC debug

[billy at dem.uminho.pt]

I tried call VecView(x, 0) in gdb but x is not a Vec and gives me an error. How
do I print the array x?  

Billy.

Quoting Barry Smith <bsmith at mcs.anl.gov>:

> 
>   Billy,
> 
>    The x array contains the vector entries. It is either that
> 1) idx == 1710 is not a valid index or more likely
> 2) x[] on input has garbage values in it.
> 
>    Can you call VecView() on x right before or after
> it is passed into the MatMult? My guess is it has
> garbage in it from earlier in the code.
> 
>    Barry
> 
> On Tue, 14 Nov 2006, billy at dem.uminho.pt wrote:
> 
> > 
> > Hi,
> > 
> > I was running my code and I got FPE error on alpha machines.
> > 
> > Using gdb the output is the following. I am using 4 processors.
> > 
> > Program received signal SIGFPE, Arithmetic exception.
> > 0x1202c4e1c in MatMult_SeqBAIJ_1 (A=0x120bbc7c0, xx=0x120be0770,
> >     zz=0x120bc9fb0) at baij2.c:260
> > 260         while (n--) sum += *v++ * x[*idx++];
> > (gdb) print n
> > $1 = 0
> > (gdb) print idx
> > $2 = (PetscInt *) 0x120c7aab8
> > (gdb) print *idx
> > $3 = 1710
> > (gdb) print v
> > $4 = (MatScalar *) 0x120c99190
> > (gdb) print *v
> > $5 = 4.0109832449655266e-12
> > (gdb) print x
> > $6 = (PetscScalar *) 0x120be1690
> > (gdb) print x[*idx]
> > $7 = 1.2349520920477556e-308
> > (gdb) print sum
> > $8 = 0
> > 
> > 
> > Billy
> > 
> 
>