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Re: Evaluating quadratic functions
From: |
hanrahat |
Subject: |
Re: Evaluating quadratic functions |
Date: |
Mon, 24 Jan 2005 03:08:27 +0000 |
That did the trick. Thanks.
-- Tom
> Tom,
>
> Try replacing the exponentiation operator ^ with the element by
> element exponentiation operator .^ (dot caret). Using ^ alone
> computes a matrix power. For that a square matrix is needed. Note that
> for a = [1 2; 3 4] , a ^ 2 and a * a give one and the same answer,
> while a .^ 2 and a .* a give one and the same different answer. a must
> be square for the former but not necessarily for the later. All are
> correct. Which is appropriate, though, depends on your purpose.
>
> Paul Laub
>
>
> On Mon, 24 Jan 2005 01:50:38 +0000, address@hidden
> <address@hidden> wrote:
> > I'm having trouble understanding how to evaluate and plot quadratic
> > functions.
> > Here's a sequence that explains what I'm trying to accomplish. In
> > particular,
> > I don't understand the error message "error: for A^b, A must be square" It
> doesn't
> > seem that A being square has anything to do with the function.
> >
> > Can anyone help me understand how to do this?
> >
> > Thanks,
> >
> > -- Tom
> >
> > GNU Octave, version 2.1.50 (i686-pc-linux-gnu).
> > Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003 John W. Eaton.
> > This is free software; see the source code for copying conditions.
> > There is ABSOLUTELY NO WARRANTY; not even for MERCHANTIBILITY or
> > FITNESS FOR A PARTICULAR PURPOSE. For details, type `warranty'.
> >
> > Please contribute if you find this software useful.
> > For more information, visit http://www.octave.org/help-wanted.html
> >
> > Report bugs to <address@hidden>.
> >
> > octave:1> x = 1:1:2;
> > octave:2> sqrt(x)
> > ans =
> >
> > 1.0000 1.4142
> >
> > octave:3> exp(x)
> > ans =
> >
> > 2.7183 7.3891
> >
> > octave:4> function retval = linear(x)
> > > retval = x + 1;
> > > endfunction
> > octave:5> linear(x)
> > ans =
> >
> > 2 3
> >
> > octave:6> function retval = quad(x)
> > > retval = x^2;
> > > endfunction
> > octave:7> quad(x)
> > error: for A^b, A must be square
> > error: evaluating binary operator `^' near line 2, column 11
> > error: evaluating assignment expression near line 2, column 8
> > error: called from `quad'
> > octave:7>
> >
> > -------------------------------------------------------------
> > Octave is freely available under the terms of the GNU GPL.
> >
> > Octave's home on the web: http://www.octave.org
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Octave is freely available under the terms of the GNU GPL.
Octave's home on the web: http://www.octave.org
How to fund new projects: http://www.octave.org/funding.html
Subscription information: http://www.octave.org/archive.html
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