From help-octave-request at bevo dot che dot wisc dot edu  Fri Aug 22 04:28:22 1997
Subject: Re: adding vectors and matrices
From: Ted dot Harding at nessie dot mcc dot ac dot uk (Ted Harding)
To: aheit at physik dot uni-kassel dot de (Andreas Heitmann)
Cc: help-octave at bevo dot che dot wisc dot edu
Date: Fri, 22 Aug 1997 10:22:20 +0100 (GMT+0100)

( Re Message From: Andreas Heitmann )
> 
> I'm using octave for some time now, but I'm still wondering if there
> is a simple way to add a fixed column vector to a number of other
> column vectors stored in a matrix. Currently i'm using a loop like the
> following:
> 
> 	v=[1;2;3];
> 	for i=1:columns(x)
> 		y(:,i)=x(:,i)+v;
> 	endfor
> 
> Is it possible to compute y without a loop statement?

Hi,

      y = x + v*ones(1,columns(x));

will do it. I understand John Eaton plans to incorporate a syntax like

      y = x .+ v

for a future release which will do the same thing (and the corresponding
thing if v is a row vector with as many elements as x has columns, i.e.
add v to each row of x).

Best wishes,
Ted.                                    (Ted dot Harding at nessie dot mcc dot ac dot uk)