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. >