TRIDIAG

AcronymDefinition
TRIDIAGTridiagonal
References in periodicals archive ?
Note that the matrices related to 1 - cos(x [+ or -] [x.sub.0]) can be treated very efficiently by multigrid, because they are nothing else than diagonally scaled versions of tridiag (-0.5,1,-0.5)--i.e., the one-dimensional Laplacian With the two (orthogonal) diagonal matrices
[A.sub.n] = (1/[h.sup.2]) * tridiag (-1,2,-1) with h = 1/n,
with [DELTA] = tridiag (-1,2,-1) denoting the one-dimensional Laplacian.