ibm_simplify: Simplify a mapper

In inlabru: Bayesian Latent Gaussian Modelling using INLA and Extensions

Simplify a mapper

Description

Implementations must return a bru_mapper object. The default method returns the result of ibm_as_taylor() for linear/affine mappers, and the original mapper for non-linear mappers.

Usage

ibm_simplify(mapper, input = NULL, state = NULL, ...)

## Default S3 method:
ibm_simplify(mapper, input = NULL, state = NULL, ...)

## S3 method for class 'bm_pipe'
ibm_simplify(
  mapper,
  input = NULL,
  state = NULL,
  inla_f = FALSE,
  ...,
  n_state = NULL
)

Arguments

mapper	A mapper S3 object, inheriting from bru_mapper.
input	Data input for the mapper.
state	A vector of latent state values for the mapping, of length ibm_n(mapper, inla_f = FALSE)
...	Arguments passed on to other methods
inla_f	logical; when TRUE for ibm_n() and ibm_values(), the result must be compatible with the INLA::f(...) and corresponding INLA::inla.stack(...) constructions. For ⁠ibm_{eval,jacobian,linear}⁠, the input interpretation may be different. Implementations do not normally need to do anything different, except for mappers of the type needed for hidden multicomponent models such as "bym2", which can be handled by bm_collect.
n_state	integer giving the length of the state vector for mappers that have state dependent output size.

Value

The original mapper is returned for non-linear mappers, and the output of ibm_as_taylor() is returned for linear mappers.

Methods (by class)

• ibm_simplify(default): Calls ibm_as_taylor() for linear mappers, and returns the original mapper for non-linear mappers.

• ibm_simplify(bm_pipe): Constructs a simplified pipe mapper. For fully linear pipes, calls ibm_as_taylor(). For partially non-linear pipes, replaces each sequence of linear mappers with a single bm_taylor() mapper, while keeping the full list of original mapper names, allowing the original input structure to be used also with the simplified mappers, since the taylor mappers are not dependent on inputs.

See Also

Other mapper methods: bru_mapper_generics, ibm_as_taylor(), ibm_eval(), ibm_eval2(), ibm_inla_subset(), ibm_invalid_output(), ibm_is_linear(), ibm_is_rowwise(), ibm_jacobian(), ibm_n(), ibm_n_output(), ibm_names(), ibm_values()

Examples

m <- bm_linear()
ibm_simplify(m, input = c(1, 3, 4, 5, 2), state = 2)

inlabru documentation built on July 28, 2026, 9:07 a.m.