Re: Creating a sign chart
- To: mathgroup at smc.vnet.net
- Subject: [mg98936] Re: Creating a sign chart
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Wed, 22 Apr 2009 05:11:37 -0400 (EDT)
- Organization: Uni Leipzig
- References: <gsivd0$9aa$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
Hi,
f[x_, y_] := x*y*Exp[-x^2 - y^2]
Plot3D[Evaluate[
Sign[Det[{{D[f[x, y], {x, 2}], D[f[x, y], x, y]},
{D[f[x, y], x, y], D[f[x, y], {y, 2}]}}]]], {x, -2,
2}, {y, -2, 2}]
??
or what ever a sign chart is ..
Regards
Jens
davef wrote:
> Is it possible to render a sign chart in Mathematica 10?
>
> Typically a sign chart is used with the first and second derivatives to identify extrema. I know there are other ways to convey this information. However, in my case I need to demonstrate a sign chart by means of an illustation. I can create a graphic in Visio and import into Mathematica but I would prefer if there were a means of generating such a chart directly in Mathematica.
>
> Something like:
>
> +++++++++++++++------------
>
>
> Thanks for any ideas.
> Dave
> x2373
>