spde.matrices {RGeostats}R Documentation

Build the Precision matrix from a set of meshes

Description

Build the Precision matrix from a set of meshes

Usage

spde.matrices(points=NA, meshes=NA, model=NA, db=NA, pattern=NA,
              nostat=NA, mode=0, 
              size=NA, lp=NA, li=NA, lx=NA, d=NA, up=NA, uj=NA, ux=NA,
              zp=NA, zi=NA, verbose = FALSE)

Arguments

points,meshes

Arguments resulting from the triangulation step. See check.mesh for explanations. These arguments are used when mode=0.

model

The model-class which provides the spatial characteristics.

db

The db-class organized as a regular grid for which the precision matrix must be determined. This argument is used when mode=2.

pattern

Definition of the SPDE pattern. It corresponds to the half-space pattern. Its dimensions are the same along all space axes. This argument is used when mode=2.

nostat

List of non-stationary parameters. For details see model.param.define.

mode

Type of construction for the SPDE matrices:

  • 0 From 'points' and 'meshes'

  • 1 From 'lp', 'li', 'lx', 'd', 'up', 'uj', 'ux', 'zp' and 'zi'

  • 2 From 'db'

Depending on this argument, one or several arrays are returned (see Details).

size

Dimension of the matrices L, U, D and Z

lp,li,lx

Definition of the L matrix which must be sparse, lower triangular, stored by column. The row indices of L must be sorted.

d

Diagonal of D, of size n

up,uj,ux

Definition of the U matrix which must be sparse, upper triangular, stored by row. The row indices of U need not be sorted. If not provided, the elements from up, ui and ux are use instead (which corresponds to the case where the initial matrix is symmetric).

zp,zi

Z is sparse, stored by column. The tow indices of Z must be sorted

verbose

Verbose flag.

Value

Several matrices used in the SPDE framework are provided depending on the 'mode' argument, such as:

According to 'mode' the following arrays are returned:

All matrices are sparse. They are returned in the 'triplet' form. Each non-zero element of the sparse matrix is specified by its row, column and the item value.


[Package RGeostats version 11.0.6 Index]