<html>
<head>
<meta content="text/html; charset=windows-1252"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<div class="moz-cite-prefix">You Wrote:<br>
<br>
If it is provided, g2() must be the jacobian of g1(): it must
compute and evaluate the partial derivatives of g1(), with respect
to x and to y.<br>
That's definitely not the case with your g2(). It should
rather return something like [2*x 2*y].<br>
<br>
I do not understand this because I am trying to solve a system of
equations and g2 represents the second equation. I suspect I am
missing something.<br>
<br>
I do not know French.<br>
<br>
Bob<br>
On 10/15/2018 5:52 PM, Samuel Gougeon wrote:<br>
</div>
<blockquote cite="mid:2de32110-fb5b-684f-22a1-afefcfdcece3@free.fr"
type="cite">
<meta content="text/html; charset=windows-1252"
http-equiv="Content-Type">
<div class="moz-cite-prefix">Hello,<br>
<br>
Le 15/10/2018 à 20:39, rsherry8 a écrit :<br>
</div>
<blockquote cite="mid:5BC4DEF8.7040508@comcast.net" type="cite">I
am trying to solve a system of two non-linear equations using
fsolve. I define the following two functions: <br>
<br>
function z=g1(x,y) <br>
z = x^2 + y^2 <br>
endfunction <br>
<br>
function z=g2(x,y) <br>
z = x^4 + y^4 - 20 <br>
endfunction <br>
<br>
When I type something like: g2(2,2) <br>
I get 12 which is right. <br>
<br>
I then run the following command: <br>
[xres]=fsolve([0,0],g1,g2); <br>
</blockquote>
<br>
If it is provided, g2() must be the jacobian of g1(): it must
compute and evaluate the partial derivatives of g1(), with respect
to x and to y.<br>
That's definitely not the case with your g2(). It should rather
return something like [2*x 2*y].<br>
<br>
For what you likely want to do, here are two examples (extracted
from a document of mine in french, sorry):<br>
<img src="cid:part1.09020906.01060500@comcast.net" alt=""
height="268" width="545"><br>
<br>
Actually, the fsolve() page is rather poor : both given examples
are about a single variable.<br>
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="https://help.scilab.org/docs/6.0.1/en_US/fsolve.html">https://help.scilab.org/docs/6.0.1/en_US/fsolve.html</a><br>
<br>
fsolve() is a key function. We should improve its help page.<br>
<br>
HTH<br>
Samuel<br>
<br>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
users mailing list
<a class="moz-txt-link-abbreviated" href="mailto:users@lists.scilab.org">users@lists.scilab.org</a>
<a class="moz-txt-link-freetext" href="http://lists.scilab.org/mailman/listinfo/users">http://lists.scilab.org/mailman/listinfo/users</a>
</pre>
</blockquote>
<br>
</body>
</html>