update.rSPDEobj {rSPDE}

Update parameters of rSPDEobj objects

Description

Function to change the parameters of a rSPDEobj object

Usage

## S3 method for class 'rSPDEobj'
update(
  object,
  user_nu = NULL,
  user_alpha = NULL,
  user_kappa = NULL,
  user_sigma = NULL,
  user_range = NULL,
  user_tau = NULL,
  user_theta = NULL,
  user_m = NULL,
  mesh = NULL,
  loc_mesh = NULL,
  graph = NULL,
  range_mesh = NULL,
  parameterization = NULL,
  ...
)

Arguments

object

The operator-based rational SPDE approximation, computed using matern.operators() with type="operator"

user_nu

If non-null, update the shape parameter of the covariance function.

user_alpha

If non-null, update the fractional order.

user_kappa

If non-null, update the range parameter of the covariance function.

user_sigma

If non-null, update the standard deviation of the covariance function.

user_range

If non-null, update the range parameter of the covariance function.

user_tau

If non-null, update the parameter tau.

user_theta

If non-null, update the parameter theta, that connects tau and kappa to the model matrices.

user_m

If non-null, update the order of the rational approximation, which needs to be a positive integer.

mesh

An optional inla mesh. Replaces d, C and G.

loc_mesh

The mesh locations used to construct the matrices C and G. This option should be provided if one wants to use the rspde_lme() function and will not provide neither graph nor mesh. Only works for 1d data. Does not work for metric graphs. For metric graphs you should supply the graph using the graph argument.

graph

An optional metric_graph object. Replaces d, C and G.

range_mesh

The range of the mesh. Will be used to provide starting values for the parameters. Will be used if mesh and graph are NULL, and if one of the parameters (kappa or tau for spde parameterization, or sigma or range for matern parameterization) are not provided.

parameterization

If non-null, update the parameterization. Only works for stationary models.

...

Currently not used.

Value

It returns an object of class "rSPDEobj. This object contains the same quantities listed in the output of matern.operators().

See Also

simulate.rSPDEobj(), matern.operators()

Examples

# Compute the operator-based rational approximation of a
# Gaussian process with a Matern covariance function on R
kappa <- 10
sigma <- 1
nu <- 0.8
range <- sqrt(8*nu)/kappa

# create mass and stiffness matrices for a FEM discretization
x <- seq(from = 0, to = 1, length.out = 101)
fem <- rSPDE.fem1d(x)

# compute rational approximation of covariance function at 0.5
op <- matern.operators(
  loc_mesh = x, nu = nu,
  range = range, sigma = sigma, d = 1, m = 2, type = "operator",
  parameterization = "matern"
)
op

# Update the range parameter of the model:
op <- update(op, user_kappa = 20)
op