Re: visualizing fields near charged objects

[Ludwik Kowalski <KowalskiL@MAIL.MONTCLAIR.EDU>]

Leigh Palmer wrote:

> >  27     ^ (+ r direction)
> >  26     |
> >  25     c
> >  24   d a b -> (+z direction
> >  23     e
> >  22
> >  21 <-(radial index)
>
> Using John's drawing above, in my implementation:
>
>                      23       25
> a <- (2a + d + b + ---- e + ---- c)/6
>                      24       24
>
> where the numerical factors come from the radial index.
>
> This form follows directly from the Laplacian. I also generate a
> row (in my case) with radial coordinates. My cells on axis have
> a different formula; the surrounding cells are unweighted for
> these cells.

This differs from the formula posted by JohnM this morning.
His was:

a <- [(b+c+d+e)+(c-e)/(2*r)]/4

Ludwik Kowalski