The data sets are generally stored in a group below the group for the mesh or grid that the dataset belongs to. The exception to this is when a file only contains data sets for an outside mesh or grid.
Scalar data sets have one value for each entity in a mesh or grid. Vector data sets may have either two (x, y) or three components (x, y, and z) depending on whether the data is 2D or 3D.
Like XMDF files themselves, data set folders are organized into directory-like group folders. In each group all subfolder names must be unique. Every scalar or vector data set has its own folder.
A data set may be steady state or time varying. Time varying data sets may begin at a specific reference time or be relative times from an arbitrary zero hour. Reference times are specified in Julian days. Time values for specific time steps are given as time offsets from either zero or from the reference time. The units for the offset times can be given in days, hours, minutes, or seconds.
1.5.6