From bug-octave-request  Mon Jun 21 14:58:22 1993
Subject: assignment to null matrices
From: hodelas at CONTROLS dot msfc dot nasa dot gov (A. Scott Hodel)
To: bug-octave
Date: Mon, 21 Jun 93 15:07:32 CDT

On a DELL '386 running Unix:
When assigning a vector as a specified column of an undefined matrix,
some odd behavior occurs:
-----------------------------------------------------------------
/home/hodelas/mfiles/hodel $ octave
Octave, version 0.72.  Copyright (C) 1992, 1993, John W. Eaton.
This is free software with ABSOLUTELY NO WARRANTY.
For details, type `warranty'.

octave:1> who				% no variables defined
octave:2> hv = ones(10,1);		% set hv = column vector
octave:3> U				% U is undefined
error: `U' undefined
octave:4> U(:,1) = hv			% assign a column of U
error: invalid assignment to scalar

octave:4> U				% U is a scalar now!  How?
U = 0
------------------------------------------------------------------
The desired behavior (to be MATLAB compatible) is to allow the statement
in line 4 to be executed if U is undefined; i.e., U column 1 is set to hv.

(Admittedly, line 4 is kludgy.)