show gradient vectors orthogonal to level curves



On S?b, 2009-10-24 at 11:51 +0200, Adam Majewski wrote:
> wxMaxima 0.8.3 http://wxmaxima.sourceforge.net
> Maxima 5.19.2 http://maxima.sourceforge.net

> plotdf does not work for me.

Do you have xmaxima installed? What's the result of the following
command:?

(%i1) plot2d(x^2,[x,0,3],[plot_format,openmath]);

Regards,
Jaime