[petsc-users] PetscViewerBinaryMatlab example for petsc-3.4.1

[Barry Smith]

  Bishesh,

    Thanks for reporting this problem. I did not fix this example when removing PetscViewerBinaryMatlabOpen() nor did I test it well before the release.  I have updated the example and made other needed changes to PETSc code in the maint branch of the PETSc repository.   All the fixes will in the next patch release of PETSc 3.4 If you would like to try the fixed code now you can follow the instructions at http://www.mcs.anl.gov/petsc/download/index.html and follow the instructions that say use

git clone -b maint https://bitbucket.org/petsc/petsc petsc

with this copy ex7.c should work correctly and bin/matlab/PetscReadBinaryMatlab.m should read the data into Matlab.

  Please let us know of any difficulties.

   Barry





On Jun 26, 2013, at 8:44 AM, Bishesh Khanal <bisheshkh at gmail.com> wrote:

> Dear all,
> I'm just starting to learn using Petsc. I was trying the example (../src/dm/examples/tutorials/ex7.c)
> for petsc-3.4.1 . However it seems this file has not been updated for the 3.4.1 version since it uses
> PetscViewerBinaryMatlabOpen() and friends which have been removed from this newer version.
> Now I tried to change them but I have some questions:
> 
> The lines I wanted to change are the ones that use following funcitons:
> 1. PetscViewerBinaryMatlabOpen(PETSC_COMM_WORLD,params->filename,&viewer)
> 2. PetscViewerBinaryMatlabOutputBag(viewer,"params",bag)
> 3. PetscViewerBinaryMatlabOutputVecDA(viewer,"da1",global,da)
> 
> For 1, it seems I can change it with:
> PetscViewerBinaryOpen(PETSC_COMM_WORLD,params->filename,FILE_MODE_WRITE,&viewer)
> PetscViewerSetFormat(viewer,PETSC_VIEWER_BINARY_MATLAB)
> 
> Now, for the 2 and 3 I thought I need to use: 
> PetscViewerBinaryWrite(PetscViewer viewer,void *data,PetscInt count,PetscDataType dtype,PetscBool istemp)
> but I'm not sure what exactly to provide as argument for count and dtype to have the same functionality as intended in ex7.c 
> I tried (for 2) using:
> ierr = PetscViewerBinaryWrite(viewer,&bag,1,PETSC_OBJECT,PETSC_FALSE);
> but it results in an error when running the executable.
> How should I count the no. of items for count variable in this case for the bag object ?
> And what should be the dtype ?
> 
> Thanks,
> Bishesh