Extract mapper information from INLA model component objects

The component definitions will automatically attempt to extract mapper information from any model object by calling the generic bru_get_mapper. Any class method implementation should return a bru_mapper object suitable for the given latent model.

Usage

bru_get_mapper(model, ...)

# S3 method for class 'inla.spde'
bru_get_mapper(model, ...)

# S3 method for class 'inla.rgeneric'
bru_get_mapper(model, ...)

# S3 method for class 'inla.cgeneric'
bru_get_mapper(model, ...)

bru_get_mapper_safely(model, ...)

Arguments

model

A model component object

...

Arguments passed on to other methods

Value

A bru_mapper object defined by the model component

Details

Before implementing your own bru_get_mapper method, check if there is already a general method available that handles your model class, such as bru_get_mapper.inla.spde(), bru_get_mapper.inla.rgeneric(), and bru_get_mapper.inla.cgeneric().

Methods (by class)

• bru_get_mapper(inla.spde): Extract an indexed mapper for the model$mesh object contained in the model object, which is assumed to be of a class supporting relevant fmesher methods.

• bru_get_mapper(inla.rgeneric): Returns the mapper given by a pre-computed mapper, a call to INLA::inla.rgeneric.q(model, cmd = "mapper") (Note: cmd="mapper" is not supported by INLA, at least not before 2025.08.17, so will be ignored), or an index mapper mapping the size of the model graph.

  The easiest method to define a mapper for an inla.rgeneric model is to store the mapper in the object. To support the function call version, add a "mapper" option to the cmd argument of your rgeneric definition function. Alternatively, define your model using a subclass and define a corresponding bru_get_mapper.<subclass> method that should return the corresponding bru_mapper object.

  If no bru_get_mapper.<subclass> method is defined, the order of precedence for the mapper construction in bru_get_mapper.<inla.rgeneric> has the following precedence:

  1. model$mapper

  2. inla.rgeneric.q(model, cmd = "mapper")

  3. bm_index() using the size of the graph returned by inla.rgeneric.q(model, cmd = "graph")

• bru_get_mapper(inla.cgeneric): Returns the mapper given by a pre-computed mapper, or an index mapper mapping the size of the model graph from INLA::inla.cgeneric.q(model)$graph.

Functions

• bru_get_mapper_safely(): Tries to call the bru_get_mapper, and returns NULL if it fails (e.g. due to no available class method). If the call succeeds and returns non-NULL, it checks that the object inherits from the bru_mapper class, and gives an error if it does not.

See also

bru_mapper for mapper constructor methods, and the individual mappers for specific implementation details.

Other mappers: bm_aggregate(), bm_collect(), bm_const(), bm_factor(), bm_fm_mesh_1d, bm_fmesher(), bm_harmonics(), bm_index(), bm_linear(), bm_logsumexp(), bm_marginal(), bm_matrix(), bm_mesh_B(), bm_multi(), bm_pipe(), bm_repeat(), bm_scale(), bm_shift(), bm_sum(), bm_taylor(), bru_mapper()

Examples

if (bru_safe_inla()) {
  library(INLA)
  mesh <- fmesher::fm_rcdt_2d_inla(globe = 2)
  spde <- inla.spde2.pcmatern(mesh,
    prior.range = c(1, 0.5),
    prior.sigma = c(1, 0.5)
  )
  mapper <- bru_get_mapper(spde)
  ibm_n(mapper)
}
#> Loading required package: Matrix
#> This is INLA_25.06.22-1 built 2025-06-22 16:17:48 UTC.
#>  - See www.r-inla.org/contact-us for how to get help.
#>  - List available models/likelihoods/etc with inla.list.models()
#>  - Use inla.doc(<NAME>) to access documentation
#> [1] 42