Re: Can You Change Domain in ListContourPlot?
- To: mathgroup@smc.vnet.net
- Subject: [mg11581] Re: Can You Change Domain in ListContourPlot?
- From: Paul Abbott <paul@physics.uwa.edu.au>
- Date: Tue, 17 Mar 1998 10:43:02 -0500
- Organization: University of Western Australia
- References: <6ec2q3$4bu@smc.vnet.net>
Chris Farr wrote:
> When I do a ListContourPlot, the domain on the horizontal axis goes from
> 1 to 2. On the vertical axis, the domain also ranges from 1 to 2.
> Thus, mathematica assumes the domain is juts the values' position in
> the matrix.
>
> What if the above is not really the domain? For example, let's say that
> (X=149, Y=15) yielded a value of 6.4. Mathematica thinks that
> (X=1,Y=1) yielded this value.
You can use MeshRange (an option for ListPlot3D, SurfaceGraphics,
ListContourPlot, ListDensityPlot and related functions which specifies
the range of x and y coordinates that correspond to the array of z
values given.).
> So, that's my question, but I would like to avoid the following solution
> to this problem, however:
>
> Create an interpolating object via ListInterpolation which transforms
> the domain from the "position in the matrix" domain to the actual
> domain. The command is the following:
>
> ListInterpolation[matrix values,{xdomain,ydomain}]
>
> Then, one could do a ContourPlot (not a ListContourPlot as it is now a
> continuous thing) on the interpolating object.
>
> This works, but my ultimate goal is to extract contour lines. The
> interpolating business causes some imprecision I would like to avoid.
But, surely, doing a ListContourPlot must also introduce some
imprecision? Since you have discrete data, how do you think
ListContourPlot can produce "exact" contour lines?
I think your solution using Interpolation will do as well. You can play
with the InterpolationOrder option if your data is sufficiently smooth.
Cheers,
Paul
____________________________________________________________________
Paul Abbott Phone: +61-8-9380-2734
Department of Physics Fax: +61-8-9380-1014
The University of Western Australia Nedlands WA 6907
mailto:paul@physics.uwa.edu.au AUSTRALIA
http://www.pd.uwa.edu.au/~paul
God IS a weakly left-handed dice player
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