[petsc-dev] [petsc4py] PETSc.Viewer().createHDF5 wipes out existing files

[Blaise Bourdin]

Hi,

> On 9 September 2010 17:40, Blaise Bourdin <bourdin at math.lsu.edu> wrote:
>> Hi,
>> 
>> I am trying to do HDF5 IO in petsc4py. I noticed that when I create a viewer using
>>  PETSc.Viewer().createHDF5(inputfile,comm= PETSc.COMM_WORLD)
>> the file "outputfile" is wiped out and replaced with a empty hdf5 container, which is bad since I am trying to read forrm it...
>> 
>> Unsurprisingly, I have no problems using the longer approach:
>>  h5in = PETSc.Viewer().create(PETSc.COMM_WORLD)
>>  h5in.setType(PETSc.Viewer.Type.HDF5)
>>  h5in.setFileMode(PETSc.Viewer.Mode.READ)
>>  h5in.setFileName(inputfile)
>> 
>> Is this expected?
>> 
> 
> Yes, it is expected. These create() methods default to mode=WRITE.
> What you and others think about this?
I would be in favor of not deleting people's files unless they explicitly ask for it ;) defaulting to append may be the best way, if it is implemented

> To open in READ mode, just do this:
> 
> PETSc.Viewer().createHDF5(inputfile, mode=PETSc.Viewer.Mode.READ,
> comm= PETSc.COMM_WORLD)
much nicer, thanks,

Blaise 

-- 
Department of Mathematics and Center for Computation & Technology
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