Re: List plotting a vector field containing invalid data
- To: mathgroup at smc.vnet.net
- Subject: [mg52148] Re: List plotting a vector field containing invalid data
- From: "Steve Luttrell" <steve_usenet at _removemefirst_luttrell.org.uk>
- Date: Fri, 12 Nov 2004 02:14:04 -0500 (EST)
- References: <cmvebb$shp$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
You can set the vector lengths to zero for the region(s) that you don't want
to plot. Here is a modified version of the example given by the Help Browser
that illustrates this idea.
<<Graphics`PlotField`
varray = Table[If[Sqrt[Abs[(i - 5.5)^2 + (j - 5.5)^2]] > 3, {Random[Real,
{-0.7, 0.7}], Random[Real, {-0.7, 0.7}]}, {0, 0}], {i, 10}, {j, 10}];
ListPlotVectorField[varray];
Steve Luttrell
"Gareth Owen" <usenet at gwowen.freeserve.co.uk> wrote in message
news:cmvebb$shp$1 at smc.vnet.net...
> I'm solving a 2D CFD problem, which is generating a lot of co-located 2D
> velocity field data, using a regular rectangular grid. Some of the grid
> is
> masked out, representing ocean bottom topography.
>
> Is there a relatively simple way to modify ListPlotVectorField to ignore
> the
> masked out values (which are stored as as unphysically large values, but
> this
> is easily modified)
>
> Thanks.
>