[Date Index] [Thread Index] [Author Index]

Re: Other bug in ContourPlot

• To: mathgroup at smc.vnet.net
• Subject: [mg81745] Re: Other bug in ContourPlot
• From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
• Date: Tue, 2 Oct 2007 05:50:05 -0400 (EDT)
• Organization: The Open University, Milton Keynes, UK
• References: <fdqbjj$ljj$1@smc.vnet.net>

Miguel wrote:

> If you run the ContourPlot a first time, it works fine. But, if you
> run ContourPlot again, the graphics previous or nothing is displayed.
> 
> http://mathematicaes.googlegroups.com/web/ContourPlotBis.pdf
> 
> The last version 6.0.1 is like a Gruyere chees: it is completed with
> innumerable holes.

It could have been an interesting claim; nevertheless it is totally 
wrong, at least from the example you gave, since the range of values 
from -6 to 6 for the variables x and y lies inside the ellipse you wish 
to plot. Therefore, Mathematica is perfectly right in drawing nothing 
since this is exactly what you asks it to do. The following draws the 
ellipse as expected:

sol = x^2/9 + y^2/16 - 25;
ContourPlot[sol == 0, {x, -20, 20}, {y, -20, 20}]

Regards,
-- 
Jean-Marc