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From: | jdonner |
Subject: | Re: matrix of variables? <- thanks |
Date: | Fri, 30 May 2003 18:53:39 -0500 |
User-agent: | Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4b) Gecko/20030513 |
Jeff wrote:
I'm trying to solve a non-linear equation with 25 vars, and it works when I number them from x(1) .. x(25) but,they naturally are a 2D array of variables, is there some way I can I use matrix notation for convenience?When I try to say this: function y = f (x) g = 0.9; # center parts y(2,2) = -1 * x(2,2) + (1/4)*g*(x(1,2) + x(2,1) + x(2,3) + x(3,2)); y(2,3) = -1 * x(2,3) + (1/4)*g*(x(1,3) + x(2,2) + x(2,4) + x(3,3)); ... more I get: error: invalid column index = 2 error: evaluating binary operator `*' near line 4, column 13 error: evaluating binary operator `+' near line 4, column 22 error: evaluating assignment expression near line 4, column 8 error: called from `f' error: fsolve: evaluation of user-supplied function failed Is there a way to do this?
Heber Farnsworth wrote:
Define x as a vector and then reshape it into a matrix within the function. x = reshape(x,5,5);
Thanks for that. Also, zeros(5,5) works as far as declaring x and y as 2D. I have to reshape at the end (I think) but at least octave is not complaining. Thanks again,
Jeff ------------------------------------------------------------- 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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