R: Update parameters of CBrSPDEobj objects

update.CBrSPDEobj {rSPDE}

R Documentation

Update parameters of CBrSPDEobj objects

Description

Function to change the parameters of a CBrSPDEobj object

Usage

## S3 method for class 'CBrSPDEobj'
update(
  object,
  user_nu = NULL,
  user_alpha = NULL,
  user_kappa = NULL,
  user_tau = NULL,
  user_sigma = NULL,
  user_range = NULL,
  user_theta = NULL,
  user_m = NULL,
  mesh = NULL,
  loc_mesh = NULL,
  graph = NULL,
  range_mesh = NULL,
  compute_higher_order = object$higher_order,
  parameterization = NULL,
  type_rational_approximation = object$type_rational_approximation,
  return_block_list = object$return_block_list,
  ...
)

Arguments

`object`	The covariance-based rational SPDE approximation, computed using `matern.operators()`
`user_nu`	If non-null, update the shape parameter of the covariance function. Will be used if parameterization is 'matern'.
`user_alpha`	If non-null, update the fractional SPDE order parameter. Will be used if parameterization is 'spde'.
`user_kappa`	If non-null, update the parameter kappa of the SPDE. Will be used if parameterization is 'spde'.
`user_tau`	If non-null, update the parameter tau of the SPDE. Will be used if parameterization is 'spde'.
`user_sigma`	If non-null, update the standard deviation of the covariance function. Will be used if parameterization is 'matern'.
`user_range`	If non-null, update the range parameter of the covariance function. Will be used if parameterization is 'matern'.
`user_theta`	For non-stationary models. If non-null, update the vector of parameters.
`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.
`compute_higher_order`	Logical. Should the higher order finite element matrices be computed?
`parameterization`	If non-null, update the parameterization. Only works for stationary models.
`type_rational_approximation`	Which type of rational approximation should be used? The current types are "chebfun", "brasil" or "chebfunLB".
`return_block_list`	Logical. For `type = "covariance"`, should the block parts of the precision matrix be returned separately as a list?
`...`	Currently not used.

Value

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

Examples

# Compute the covariance-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_cov <- matern.operators(
  loc_mesh = x, nu = nu,
  range = range, sigma = sigma, d = 1, m = 2,
  parameterization = "matern"
)
op_cov

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