Erase menu

Press and hold to access erasing operations.

Complement
  Clicking here causes erased points to become visible and visible
  points to become erased.  There is no Undo operation for
  erasing, but by using a combination of Complement and Erase, a
  user can recover particular points that were previously erased.

Delete erased
  Click on this button to specify that erased points should be
  treated as "deleted."  When the data are standardized or scaled,
  it will be as if those points are not there.

Undelete
  Restore the "deleted" points.  They will still be erased, but
  they will be included in data standardization and scaling.

Restore erased points  
  Make all points visible.

