tweaking VectorPlot...
- To: mathgroup at smc.vnet.net
- Subject: [mg111247] tweaking VectorPlot...
- From: J Davis <texasautiger at gmail.com>
- Date: Sun, 25 Jul 2010 01:57:45 -0400 (EDT)
Looking at this example in the documentation...
points = {{-1, -1}, {-1, 1}, {1, -1}, {1, 1}}; VectorPlot[{-1 - x^2 +
y, 1 + x - y^2}, {x, -2, 2}, {y, -2, 2}, VectorPoints -> points,
VectorScale -> .25,
Epilog -> {Red, PointSize[Medium], Point[points]}]
I would prefer for the *tail* of the vector to be situated at "points"
rather than the tip (or as Mathematica draws them, the base of the
arrowhead at the tip).
I was hoping there was an option I could call to VectorPlot to make
the desired behavior happen but I don't find any.
Suggestions? Or do I need to manually translate all the vectors? I was
hoping to avoid that since students would be utilizing the code and I
want to keep it as clean and simple as possible.
Once I accomplish the task above, I was looking for a clean way to
plot the level curves of a surface and then superimpose the gradient
vector field---but here's the catch---where the only vectors shown
were the ones along the level curves (meaning their *tails* are along
the level curves). I tried RegionFunction but didn't get satisfactory
results.
Any help is appreciated.
Thanks,
John