|Chronology||Current Month||Current Thread||Current Date|
|[Year List] [Month List (current year)]||[Date Index] [Thread Index]||[Thread Prev] [Thread Next]||[Date Prev] [Date Next]|
On Fri, 9 Feb 2001, Ludwik Kowalski wrote:
And what is the corresponding formula for "a" when it has
six neighbors (3-dim)? Suppose f and g are added in the phi
direction. I do not trust myself in trying to answer this
question on the basis of the general theoretical formula.
You don't want to (and really can't, I think) go there with a 2-d
spreadsheet. Fortunately, the isolated disk capacitor has
azimuthal symmetry so all derivatives in the phi direction vanish.
The spreadsheet universe for this problem is a plane that includes
the symmetry axis and the full 3-d picture emerges by rotating it
around that axis.
Similarly BTW, In the usual 2-d cartesian relaxation scheme, we
implicitly assume no out-of-the-plane variations. John D's "dog"
is not, therefore, "one block thick." It is a cross sectional
slice of a structure that is extended infinitely in both
directions in and out of the plane.