This function creates a new file or opens an existing one.
Result = EOS_PT_OPEN( fieldname [, /CREATE] [, /RDWR | , /READ] )
Returns the point file id handle (fid) if successful and FAIL (-1) otherwise.
Complete path and filename (string) for the file to be opened.
If file exists, delete it, then open a new file for read/write.
Open for read/write. If file does not exist, create it.
Open for read only. If file does not exist then error.
In this example, we create a new point file named, PointFile.hdf. It returns the file handle, fid.
fid = EOS_PT_OPEN("PointFile.hdf", /CREATE)