saving parallel vectors

[Matteo Semplice]

Thansk for all the replies.

I always thought that binary format would be best, but I couldn't find any 
description of the binary format. Could you point me to a relevant piece 
of the docs? Can I load the PETSC binary files into MatLab or DataExplorer 
for further processing and visualization?

Matteo

On Thu, 23 Nov 2006, Barry Smith wrote:

>  NEVER use ascii for large data sets. Use the binary viewer to save
> them. See PetscViewerBinaryOpen().
>
>   Barry
>
>
> On Thu, 23 Nov 2006, Matteo Semplice wrote:
>
>> This is really a newbie question but I am struggling to solve out of memory
>> troubles on my first processor.
>>
>> I have a parallel global vector, say v, that I obtain with a call to
>> DAGetGlobalVector. I save it to disk opening an ASCII standard viewer on
>> PETSC_COMM_WORLD and calling VecView. As I understand from the manual, this
>> causes all processors to send their data to the first one and this one writes
>> them to disk. This works fine for small computational grids, but hangs my
>> program if the grid is bigger.
>>
>> I am thinking to get each processor to write its own file and reassemble the
>> data at the end of the program. I tried to create the viewer with the
>> communicator PETSC_COMM_SELF and issue VecView. I get as many files as
>> processors, but the first one contains all the data and the others are empty!
>>
>> Why? And, more importantly, what's the best way to achieve my goal?
>>
>> Thanks a lot.
>>
>>      Matteo
>>
>>
>

-- 
--
Matteo Semplice
Dip. di Matematica - Universita` degli Studi di Milano
Via Saldini, 50 - 20133 MILANO.   Tel: +39 02 50316170