kcrisman wrote:
> 
> 
> On Oct 13, 6:05 pm, "[email protected]" <[email protected]> wrote:
>> Hello all, is there any other possibility how to plot implicit
>> function than implicitplot?
>>
>> I do not like implicitplot too much, since it is in fact countourplot
>> and it is not easy to set the color (for example).
> 
> There is not currently any other way to do this, I think.  A colleague
> of mine has some experimental code to implicit plot the "right" way
> (by following derivatives around and spot-checking nearby to not miss
> components, I guess), but doesn't consider it ready for prime time
> yet.


How do you do an implicit plot "right"?  Scipy has tools for numerical 
integration (you mention following derivatives), if that helps.

A quick google search turns up several references to software: 
http://geomblog.blogspot.com/2008/01/plotting-implicit-functions-bleg.html

The maple help page may help: 
http://www.maplesoft.com/support/help/Maple/view.aspx?path=plots/implicitplot

This issue has come up before on the list (and Josh Kantor gave an 
algorithm and a reference): 
https://groups.google.com/group/sage-devel/browse_thread/thread/6b1d3d0f06db9c6a

More references and algorithms: 
http://www.tangentspace.net/cz/archives/2007/08/implicit-plotting-code-for-mathematica/

Mma also says: ContourPlot initially evaluates f at a grid of equally 
spaced sample points specified by PlotPoints. Then it uses an adaptive 
algorithm to subdivide at most MaxRecursion times to generate smooth 
contours. http://reference.wolfram.com/mathematica/ref/ContourPlot.html

Jason


-- 
Jason Grout


--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to 
[email protected]
For more options, visit this group at 
http://groups.google.com/group/sage-support
URL: http://www.sagemath.org
-~----------~----~----~----~------~----~------~--~---

Reply via email to