From help-octave-request at bevo dot che dot wisc dot edu  Mon Jan 29 07:41:48 2001
Subject: Re: Nonconformant \ behaviour
From: "Johan Kullstam" <kullstam at ne dot mediaone dot net>
To: help-octave at bevo dot che dot wisc dot edu
Date: 29 Jan 2001 08:44:19 -0500

"Richard Gould" <gouldr at one dot net dot au> writes:

> In matlab, the command sequence:
> 
> A=[1,2,3,4];
> b=[1];
> x=A\b
> 
> gives x=[0;0;0;0.2500]
> 
> Whilst in octave, this produces the message:
> 
> "error: operator \: nonconformant arguments (op1 is 1x4, op2 is 1x1)"

> Is there a way of working around this apparent discrepency?

try

x = pinv(A)*b;

but this gives

jk:4> pinv(A)*x
ans =

  0.033333
  0.066667
  0.100000
  0.133333

i am not sure what you expect A\b to do.  it's underdetermined so i
guess matlab just picks a working solution.  you could just take
a/some column(s) of A and divide those into b.  this gives you a
partial x.  fill with zeros to taste.

-- 
J o h a n  K u l l s t a m
[kullstam at ne dot mediaone dot net]
Don't Fear the Penguin!



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