Re: Bug in ListContourPlot?
- To: mathgroup at smc.vnet.net
- Subject: [mg118663] Re: Bug in ListContourPlot?
- From: Peter Pein <petsie at dordos.net>
- Date: Fri, 6 May 2011 07:24:01 -0400 (EDT)
- References: <ipbg07$agf$1@smc.vnet.net>
Am 28.04.2011 12:36, schrieb Barak Shoshany:
> Please copy and paste this into a Mathematica notebook:
>
> ListContourPlot[{{0.42256875000000005`, 3091.38125`,
> 8.271213205043878`}, {0.42256875000000005`, 3092.00625`,
> 6.266039117378199`}, {0.4263187500000001`, 3091.38125`,
> 5.613752062730342`}, {0.4263187500000001`,
> 3092.00625`, -5.684341886080802`*^-14}, {0.4263187500000001`,
> 3092.63125`, 5.599651386371079`}, {0.43006875000000006`,
> 3092.00625`, 6.059667975471868`}}]
>
> When I execute this code on my computer (Mathematica v8.0.1, Windows 7
> x64), the Mathematica kernel hangs. Does this happen to anyone else as
> well?
>
> Barak
>
Hi!
Just a (late) proposal for cases like this:
Try to rationalize the values, but _not_ to full precision:
ListContourPlot[
tbl = Rationalize[intbl={{0.42256875000000005`, 3091.38125`,
8.271213205043878`}, {0.42256875000000005`, 3092.00625`,
6.266039117378199`}, {0.4263187500000001`, 3091.38125`,
5.613752062730342`}, {0.4263187500000001`,
3092.00625`, -5.684341886080802`*^-14}, {0.4263187500000001`,
3092.63125`, 5.599651386371079`}, {0.43006875000000006`,
3092.00625`, 6.059667975471868`}}, 10^-$MachinePrecision]]
works great on Version 8.01/Win7-64 and reveals a set of levels of
contours like concentric squares.
But be sure, not to use "Rationalize[....,0]"!
As a measure for the error,
tbl - intbl // Flatten // Norm
--> 8.98526*10^-16
seems small enough to me.
Cheers,
Peter