Fieldconvert allows for a sub-range of the mesh (computational domain) by using an xml input option and either convert or manipulate the Nektar++ output binary files. Taking as an example the conversion of the Nektar++ binary files (.chk or .fld) shown before and wanting to convert just the 2D sub-range defined by -2 ≤x ≤ 3, -1 ≤y ≤ 2 can be acheived as follows:
Paraview or VisIt (.vtu format)
FieldConvert test.xml:xml:range=‘‘-2,3,-1,2’’ test.fld test.vtu
Tecplot (.dat format)
FieldConvert test.xml:xml:range=‘‘2,3,-1,2’’ test.fld test.dat
where the range information defines the range option of xml input module, the two first
numbers define the range in x direction and the the third and fourth number specify the y
range. A sub-range of a 3D domain can also be specified. For doing so, a third set of numbers
has to be provided to define the z range.
Fieldconvert also allows for a sub-range of the mesh base on the composite definition of the
boundaries of hte domain. Using the xml input option comprange one can specify the elements
that only touch the surface composite. This can be useful processing boundary expasnions
such as the extract module since it will only setup the volume mesh touching the composites
associated with the boundary reducing the memory ane execution time to extract a surface
field or process the wall shear stress. As an exmple consider the extraction of a surface field on
boundary 3 which is associated with the mesh composties 1,2 then you can specify
FieldConvert -m extract:bnd=3 test.xml:xml:comprange=‘‘1,2’’ test.fld bnd.fld