Re: PlotVectorField

• To: mathgroup at smc.vnet.net
• Subject: [mg34789] Re: PlotVectorField
• From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
• Date: Fri, 7 Jun 2002 01:08:51 -0400 (EDT)
• Organization: Universitaet Leipzig
• Sender: owner-wri-mathgroup at wolfram.com

```Hi,

what is with

PlotVectorField[{1, 4 - x^2 - y^2}, {x, -3, 3}, {y, -3, 3},
ScaleFunction -> (1 &), PlotPoints -> 9, ScaleFactor -> 0.75,
PlotRange -> All]

??
Regards
Jens

Selwyn Hollis wrote:
>
> I have a situation where I need to PlotVectorField with a specific
> PlotRange. For example,
>
> <<Graphics`PlotField`;
> PlotVectorField[{1,4-x^2-y^2},{x,-3,3},{y,-3, 3},
>   ScaleFunction->(1&), PlotPoints -> 9, ScaleFactor -> 0.75,
>   PlotRange->{{-3.2, 3.2},{-3.2, 3.2}}]
>
> As happens with that example, arrows near the edge often get chopped
> off. That's to be expected. What I'd like to do is use PlotRegion to
> create ``margins" around the plot so that all the arrows are fully
> visible. For example,
>
> PlotVectorField[{1,4-x^2-y^2},{x,-3,3},{y,-3, 3},
>   ScaleFunction->(1&), PlotPoints -> 9, ScaleFactor -> 0.75,
>   PlotRange->{{-3.2, 3.2},{-3.2, 3.2}}, PlotRegion->{{.1,.9},{.1,.9}}]
>
> This brings the heads of the arrows back into the picture, but the
> lines don't connect with the heads. In other instances, heads get
> drawn badly and look like boxes.
>
> Short of changing the PlotRange, xmin, xmax, ymin, ymax values, is
> there some better way to do this?
>
> And is this an ``issue" with PlotVectorField?
>