Stability and convergence of the Dirichlet difference problem 269
In this case the function D( x) takes on the value
D(x) = A(x) -
~EP att' (x)
Etfo
B(J:,~)
= A(J:) - [ ~ B(x, ~) - B(x, ~ 0 )]
EEPatt'(x)
srnce A( x) = L B( x, 0 for the Laplace equation. This provides
EEPatt'(x)
support for the view that
D(x) = B(x, x(+l,,)) > 0.
If a node x is near-boundary not only with respect to .r °', but also in
other directions, then sum ( 12) contains no other terms for~ = ~ 1 , ~ 2 , ..• , ~ k,
so that
Let x E w 7, be a near-boundary and irregular node only in some di-
rection Xa and ~ 0 = x(+i") E /h, x(-!") E wh. From the equation
where
p
A~w+ L A(Jw=-<p*(x),
(3= l
(3 ;t °'
A(J y = Yx13:r13'