spde.matrices {RGeostats}  R Documentation 
Build and return the Precision matrix
spde.matrices(dbin=NA, dbout=NA, model, triswitch="nqQ", nostat=NA, gext=NA, points=NA, meshes=NA, type=1, flag.Q=FALSE, flag.G=TRUE, flag.std=FALSE, flag.blin=FALSE, verbose = FALSE)
dbin 
The 
dbout 
The 
model 
The 
triswitch 
Command line for the internal triangulation step. For more information see

nostat 
List of nonstationary parameters.
For details see 
gext 
When 'dbout' is organized as a grid, it may be dilated by gext. This argument designates an array, with its dimension equal to the dimension of the space and which contains the extension defined in number of grid nodes. If not defined, the grid is not dilated and the simulated results may suffer some edge effect problems. 
points,meshes 
Arguments resulting from the triangulation step. See

type 
Coarsening mode. It may be either 0 for the standard coarsening. When strictly positive, a coarse sample is kept only if at least 'type' pathes exist between two coarse samples of the standard coarsening algorithme. 
flag.Q 
When TRUE, the Q sparse matrix is output (in triplet format). 
flag.G 
When TRUE, the B and G sparse matrices (in triplet format), as well as the TildeC and Lambda vectors are output. 
flag.std 
When TRUE, the Vars vector is output. 
flag.blin 
When TRUE, the blin vector is output. 
verbose 
Verbose flag. 
Several vectors or matrices used in the SPDE framework are provided such as:
Q The precision matrix (in triplet format)
G The G array
B The B array: C^(1/2) * G * C^(1/2)
TildeC The vector C vector (used for anisotropy and range)
Lambda The L vector (used for sill): L = (Lb * C)^(1/2)
Vars The diagonal of the inverse Q matrix
blin The array of coefficients used to construct Q
indCo The list of coarse(1) or fine(0) samples
L The L array (connectivity sparse matrix)
Note that:
Q is produced if 'flag.Q' is TRUE
G, B, TildeC and Lambda are produced if 'flag.G' is TRUE
Stdv is produced if 'flag.std' is TRUE
blin is produced if 'flag.blin' is TRUE
All matrices are sparse. They are returned in the 'triplet' form. Each nonzero element of the sparse matrix is specified by its row, column and the item value.