Splotting of multi mesh data files can be controlled via the index modifier.
 A data file can contain more than one mesh, and in that case all meshes
 in the file will be splotted by default. Meshes are separated from each
 other, in the data file, by double blank lines. To splot a single mesh in
 a multi mesh file use the index modifier which specify which mesh to splot.
 First mesh is mesh 0.

 Example:

 splot "data1" index 2 with points

 will splot the third mesh in file data1 with points.