*! version 1.3 25oct2020

Title

frameappend -- Append frames

Syntax

frameappend
framename
[, drop]

drop drops the frame framename after it has been appended

Description

frameappend appends the contents of to current frame. The new
observations will be at the bottom of the current frame.

The command works for variable names that begin with an underscore.

Author

Jeremy Freese, Stanford University, jfreese@stanford.edu

Revision uses improvements provided by Daniel Fernandes and Roger Newson.