Data formats

VIGIE uses an internal data format. All user's data will be converted into this internal data format. This conversion is automatically realized by VIGIE and is transparent to the user but the user can also define its own interface between a new data format and VIGIE internal data format. For the user who does not want to define his own interface, several interfaces using simplified data formats are provided and will be described below. The kind of interface that you are using is told to VIGIE by the description file. The use of the description file is mandatory : This is the first file that is read by VIGIE and it provides the necessary informations about the format used, the path to the different data files, the names of the variables and the extra variables that have to be computed from the known ones. Section 2.9 describes the description file.

VIGIE uses two different types of interfaces :

The first class accepts ascii data generated by any type of formatted writing instruction.

The second class uses the standard IEEE 32 bits binary format (real*4 in fortran). Binary formats depend on the machine you are. However, many compilers include an option to convert their specific binary format into the standard IEEE 32 bits binary format.

It is advisable to use binary format for huge data set and to reserve the use of ascii interface to moderate or small data set.

$\bullet$ The first implemented and most general binary format is called the HDB format. It can handle 2-D or 3-D meshes, structured or not with several blocks or not, with an arbitrary number of variables. It also includes the possibility to define fictitious boundaries to display particular values of interest to the user on these boundaries. Note that the variables located on the fictitious boundaries can be different from the ones located at the mesh nodes.

$\bullet$ HFEP (High Frequency Electromagnetic Problems) is a modifed version of HDB specialized for 2-D electromagnetic problems. This interface does not include the possibility to define fictitious boundaries, but allows the affectation of a logic number to surface elements.

$\bullet$ RCS (Radar Cross Section) is a binary format specialized in 1-D representation.

$\bullet$ MOVING is an ascii format specialized to 3-D unstructured tetraedral meshes. It allows the use of an arbitrary number of variables and also includes the possibility to redefine the values of the coordinates of the mesh points.

$\bullet$ ASCII2D is an ascii format specialized to 2-D general unstructured meshes. It allows the use of an arbitrary number of vectorial and scalar variables.

$\bullet$ ASCII1D is an ascii format specialized to 1-D applications.





First find which format matches best with your data, and then write a description file (cf section 2.9) which will be read by VIGIE and define which kind of format is used.