[Dune-devel] [Dune-Commit] [Commit] dune-grid - 545f73a: Start working on a backup restore facility in YaspGrid

[Oliver Sander]

Hi Dominic,

> when I implemented the facility I didnt have any higher goal in mind than
> making a currently unavailable feature available within a day or two. So my
> implementation is simple and straight-forward. What you, Oli and Martin,
> are aiming for are higher goals, that seem out of scope for me.

please don't feel offended.  Your work is much appreciated.



> - Concerning VTK, it seems to me that such functionality is definitely to
> be discussed at a higher level. The reason "this way I can look at my
> backup in paraview" isnt worth the effort IMO. Using VTKWriter with a
> trivial solution (or allowing it to be called without solution) would do
> that very same trick. Do you often do that?

Yes, I do.

In your case, writing a simple ascii VTK file is hardly more challenging than
writing a homebrew ascii format.  Reading is a bit more difficult, but since
you rightly said that you expect the BackupRestore thing to only read files
that it has written itself, it should not be much more difficult.
To illustrate my point, please find appended below a small VTK example file for
a tensor-product grid.  I can read and display this file using ParaView.
Note also the non-vtk line 2

  <MagicYaspGridValue> 42 </MagicYaspGridValue>

which doesn't seem to pose a problem.

Please reconsider whether you need your own format.

Cheers,
Oliver



<VTKFile type="RectilinearGrid" version="0.1" byte_order="LittleEndian">
  <MagicYaspGridValue> 42 </MagicYaspGridValue>
  <RectilinearGrid WholeExtent="0 3 0 10 0 10">
  <Piece Extent="0 3 0 10 0 10">
   <Coordinates>
      <DataArray type="Float64" format="ascii">
        -7.5
        -3
         0
         4
      </DataArray>
      <DataArray type="Float64" format="ascii">
        -3
        -2.90625
        -2.8125
        -2.71875
        -2.625
        -2.53125
         2.625
         2.71875
         2.8125
         2.90625
         3
      </DataArray>
      <DataArray type="Float64" format="ascii">
        -3
        -2.875
        -2.75
        -2.625
        -2.5
        -2.375
         2.5
         2.625
         2.75
         2.875
         3
      </DataArray>
    </Coordinates>
  </Piece>
  </RectilinearGrid>
</VTKFile>


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