# Need help with 3d plotting Vector Field.

## Main Question or Discussion Point

I am in real need for a graphical application with 3d plotting capabilities.
I need to plot some particles given their space coordinate. This has been well managed using VMD. But i am clueless how to plot associated velocity vector with particles. So basicall i am looking for to plot velocity field.
I have already done similar things in 2d with xmgrace. such nice apps. but gnuplot is not good at all for 3d plotting specially the field.

My data sets are: for position plot in 3d (x, y, z)
for velocity fields in 3d (x, y, z, vx, vy, vz)
(it will look like some arrows in space)

Any help will be highly sppreciated and i am sad to say that i need suggestion urgently as my report submission date is very close.

regards.

## Answers and Replies

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minger
Science Advisor
If you are on a linux box, you can use Plot3d which is available through the NASA Advanced Supercomputing Division (NAS) website: https://www.nas.nasa.gov/cgi-bin/software/start

You will have to apparently request it though.

If you do use it, note that it was originally developed for CFD. As such, it requires a flow file which contains 5 vectors (mass, x/y/z momentum, and energy). In order to get velocity vectors, you would need to write your velocity components as x/y/z momentum, and then make sure that density is 1.0 for all points. Energy can then be zero. The call to get the vector would then be
re/for/mgr/3d !--read a formatted multiblock 3d file
grid.file
results.file

fun 200 !--velcocity vector function
vec/sca=153 !--scale the velocity vector by velocity magnitude
[lots of options here]
pl !--plot

edit: You can also try FAST available at the same location, which isn't quite as tailored to CFD. I haven't really used it though, so I can't offer any advice.

Thanks, i'll definitely try ur suggestion. But any other easily available apps. Sending mail seems to me wired :(

minger
Science Advisor
That's all I got. You don't mean snail mail do you? It seemed to me that all you needed was to essentially register with the site.

try Maple