Reference: savePointSetToFile
savePointSetToFile(set, fn) saves the point set set to the file with name fn, a string containing a fully-qualified file name, including extension ".asd".
Important! If the set set contains other elements than real points (vectors), only the real points (vectors) will be saved, and no other elements.
By default, the coordinates of the points are saved with extended precision (10 bytes per coordinate). You can also choose double precision (8 bytes per coordinate) or single precision (4 byte per coordinate), by specifying "extended", "double", or "single" as a third parameter (a string).