makeprec {spam} | R Documentation |
Creates precision matrices for gridded GMRF.
make.prec(par, dims, model = "m1p1", eps = .Spam$eps)
par |
parameters used to construct the matrix. |
dims |
dimension of the grid. |
model |
see details and examples. |
eps |
A tolerance parameter: elements of 'x' such that 'abs(x) <= eps' set to zero. Defaults to 'eps = .Spam$eps' |
The function should be illustrative on how to create precision matrices for gridded GMRF. Hence, no testing (positive definiteness is done). Please see the examples on the meaning of the different models.
A spam
matrix of dimension prod(dims)
xprod(dims)
.
Reinhard Furrer
as.matrix(make.prec(c(.4), c(4,3),'m1p1')) as.matrix(make.prec(c(.4,.3), c(4,3),'m1p2')) as.matrix(make.prec(c(.4,.3,.2), c(4,3),'m2p3')) as.matrix(make.prec(c(.4,.3,.2,.1),c(4,3),'m2p4'))