MaplePrimes - answers and comments on Question, fieldplot3d arrows

fieldplot3d

Robert Israel — Tue, 27 May 2008 23:05:00 Z

The only options for the arrows in fieldplot3d are LINE, THIN, SLIM, THICK, and `3-D`.
An alternative might be to compute a list of individual vectors and plot them using either plottools[arrow] or plots[arrow].

Ok, any suggestions on code?

barretbp — Wed, 28 May 2008 00:06:55 Z

So I am trying to plot this vector field:

<4x,4y,2> and use the arrow from plottools to plot these vectors because I don't like the was fieldplot3d does it.

arrow(basepoint,dir,options) is the code I am using, basically this:

arrow(vector([x,y,z]), F, .2, .4, .1, cylindrical_arrow):
where F is the field above.

I can't seem to get this to work. Any suggestions? I am baically tying to take a field F, and create a list of vectors to plot in plot3d, but am unsure how to calculate these vectors and turn them into arrows.

Thanks much!

Thank you!

barretbp — Wed, 28 May 2008 20:34:27 Z

Thanks so much, that worked perfectly!!!

Cylindrical arrows

Robert Israel — Wed, 28 May 2008 10:30:30 Z

First get the list of base points, e.g.

> basepts := [seq(seq(seq( 2*[x,y,z], x = -2 .. 2), y = -2 .. 2), z = -2 .. 2)]:

Now write a function that takes a base point and returns the corresponding arrow.

> makearrow:= P -> plottools:-arrow(P, <0.4*P[1], 0.4*P[2], 1>, 
   .2, .4, .3, cylindrical_arrow, fringe=black) ;

Apply this to each base point, and display the result.

> plots[display](map(makearrow, basepts), scaling=constrained, 
     axes=box);