Package: wnpp
Severity: wishlist
Owner: Alastair McKinstry <mckins...@debian.org>

* Package name    : xdmf
  Version         : 2.1
  Upstream Author : Name <somebody@
* URL             : http://www.xdmf.org/
* License         : BSD
  Programming Lang: C++, Python, Fortran
  Description     : eXtensible Data Model and Format library

The need for a standardized method to exchange scientific data between High 
Performance Computing codes and tools lead to the development of the eXtensible 
Data Model and Format (XDMF) . Uses for XDMF range from a standard format used 
by HPC codes to take advantage of widely used visualization programs like 
ParaView, to a mechanism for performing coupled calculations using multiple, 
previously stand alone codes.

Data format refers to the raw data to be manipulated. Information like number 
type ( float, integer, etc.), precision, location, rank, and dimensions 
completely describe the any dataset regardless of its size. The description of 
the data is also separate from the values themselves. We refer to the 
description of the data as Light data and the values themselves as Heavy data. 
Light data is small and can be passed between modules easily. Heavy data may be 
potentially enormous; movement needs to be kept to a minimum. Due to the 
different nature of heavy and light data, they are stored using separate 
mechanisms. Light data is stored using XML, Heavy data is typically stored 
using HDF5. While we could have chosen to store the light data using HDF5 
attributes using XML does not require every tool to have access to the compiled 
HDF5 libraries in order to perform simple operations.

Data model refers to the intended use of the data. For example, a three 
dimensional array of floating point vales may be the X,Y,Z geometry for a grid 
or calculated vector values. Without a data model, it is impossible to tell the 
difference. Since the data model only describes the data, it is purely light 
data and thus stored using XML. It is targeted at scientific simulation data 
concentrating on scalars, vectors, and tensors defined on some type of 
computational grid. Structured and Unstructured grids are described via their 
topology and geometry. Calculated, time varying data values are described as 
attributes of the grid. The actual values for the grid geometry, connectivity, 
and attribute values are contained in the data format. This separation of data 
format and model allows HPC codes to efficiently produce and store vales in a 
convenient manner without being encumbered by our data model which may be 
different from their internal arrangement.


XDMF uses XML to store Light data and to describe the data Model. HDF5 is used 
to store Heavy data. The data Format is stored redundantly in both XML and 
HDF5. This allows tools to parse XML to determine the resources that will be 
required to access the Heavy data. 


 XDMF is used in the visualization tools Paraview (already in Debian) and VisIt 
(which I am packaging).



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