Getting y(:)=x to work when y has not yet been defined?

[Alvin Garcia]

Hello,
        I was wondering if there is some option that will enable Octave to 
allow statements like, as allowed in MATLAB:

y(:)=x

where x is an arbitrary vector, and y has not previously been defined.  
This question was also posted by address@hidden on Sep-06-95, and 
a response was posted by address@hidden on the same day.  However, the 
posted answer said that such assignments would work if y and x are of the 
same size.  I am interested in the case in which y has not previously been 
defined.  

All suggestions are appreciated.  

Thanks.

-Alvin