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inlabru (version 2.6.0)

like: Likelihood construction for usage with bru()

Description

Likelihood construction for usage with bru()

Usage

like(
  formula = . ~ .,
  family = "gaussian",
  data = NULL,
  response_data = NULL,
  mesh = NULL,
  E = NULL,
  Ntrials = NULL,
  weights = NULL,
  samplers = NULL,
  ips = NULL,
  domain = NULL,
  include = NULL,
  exclude = NULL,
  allow_latent = FALSE,
  allow_combine = NULL,
  control.family = NULL,
  options = list(),
  .envir = parent.frame()
)

like_list(...)

# S3 method for list like_list(object, envir = NULL, ...)

# S3 method for bru_like like_list(..., envir = NULL)

# S3 method for bru_like_list [(x, i)

Value

A likelihood configuration which can be used to parameterize bru().

Arguments

formula

a formula where the right hand side is a general R expression defines the predictor used in the model.

family

A string identifying a valid INLA::inla likelihood family. The default is gaussian with identity link. In addition to the likelihoods provided by inla (see names(INLA::inla.models()$likelihood)) inlabru supports fitting latent Gaussian Cox processes via family = "cp". As an alternative to bru(), the lgcp() function provides a convenient interface to fitting Cox processes.

data

Likelihood-specific data, as a data.frame or SpatialPoints[DataFrame] object.

response_data

Likelihood-specific data for models that need different size/format for inputs and response variables, as a data.frame or SpatialPoints[DataFrame] object.

mesh

An inla.mesh object. Obsolete.

E

Exposure parameter for family = 'poisson' passed on to INLA::inla. Special case if family is 'cp': rescale all integration weights by E. Default taken from options$E, normally 1.

Ntrials

A vector containing the number of trials for the 'binomial' likelihood. Default taken from options$Ntrials, normally 1.

weights

Fixed (optional) weights parameters of the likelihood, so the log-likelihood[i] is changed into weights[i] * log_likelihood[i]. Default value is 1. WARNING: The normalizing constant for the likelihood is NOT recomputed, so ALL marginals (and the marginal likelihood) must be interpreted with great care.

samplers

Integration domain for 'cp' family.

ips

Integration points for 'cp' family. Overrides samplers.

domain

Named list of domain definitions.

include

Character vector of component labels that are needed by the predictor expression; Default: NULL (include all components that are not explicitly excluded)

exclude

Character vector of component labels that are not used by the predictor expression. The exclusion list is applied to the list as determined by the include parameter; Default: NULL (do not remove any components from the inclusion list)

allow_latent

logical. If TRUE, the latent state of each component is directly available to the predictor expression, with a _latent suffix. This also makes evaluator functions with suffix _eval available, taking parameters main, group, and replicate, taking values for where to evaluate the component effect that are different than those defined in the component definition itself (see component_eval()). Default FALSE

allow_combine

logical; If TRUE, the predictor expression may involve several rows of the input data to influence the same row. Default FALSE, but forced to TRUE if response_data is NULL or data is a list

control.family

A optional list of INLA::control.family options

options

A bru_options options object or a list of options passed on to bru_options()

.envir

The evaluation environment to use for special arguments (E, Ntrials, and weights) if not found in response_data or data. Defaults to the calling environment.

...

For like_list.bru_like, one or more bru_like objects

object

A list of bru_like objects

envir

An optional environment for the new bru_like_list object

x

bru_like_list object from which to extract element(s)

i

indices specifying elements to extract

Author

Fabian E. Bachl bachlfab@gmail.com

Details

  • like_list: Combine a bru_like likelihoods into a bru_like_list object

  • like_list.list: Combine a list of bru_like likelihoods into a bru_like_list object

  • like_list.bru_like: Combine several bru_like likelihoods into a bru_like_list object

Examples

Run this code
# \donttest{
if (bru_safe_inla() &&
    require(ggplot2, quietly = TRUE)) {

  # The like function's main purpose is to set up models with multiple likelihoods.
  # The following example generates some random covariates which are observed through
  # two different random effect models with different likelihoods

  # Generate the data

  set.seed(123)

  n1 <- 200
  n2 <- 10

  x1 <- runif(n1)
  x2 <- runif(n2)
  z2 <- runif(n2)

  y1 <- rnorm(n1, mean = 2 * x1 + 3)
  y2 <- rpois(n2, lambda = exp(2 * x2 + z2 + 3))

  df1 <- data.frame(y = y1, x = x1)
  df2 <- data.frame(y = y2, x = x2, z = z2)

  # Single likelihood models and inference using bru are done via

  cmp1 <- y ~ -1 + Intercept(1) + x
  fit1 <- bru(cmp1, family = "gaussian", data = df1)
  summary(fit1)

  cmp2 <- y ~ -1 + Intercept(1) + x + z
  fit2 <- bru(cmp2, family = "poisson", data = df2)
  summary(fit2)

  # A joint model has two likelihoods, which are set up using the like function

  lik1 <- like("gaussian", formula = y ~ x + Intercept, data = df1)
  lik2 <- like("poisson", formula = y ~ x + z + Intercept, data = df2)

  # The union of effects of both models gives the components needed to run bru

  jcmp <- ~ x + z + Intercept(1)
  jfit <- bru(jcmp, lik1, lik2)

  # Compare the estimates

  p1 <- ggplot() +
    gg(fit1$summary.fixed, bar = TRUE) +
    ylim(0, 4) +
    ggtitle("Model 1")
  p2 <- ggplot() +
    gg(fit2$summary.fixed, bar = TRUE) +
    ylim(0, 4) +
    ggtitle("Model 2")
  pj <- ggplot() +
    gg(jfit$summary.fixed, bar = TRUE) +
    ylim(0, 4) +
    ggtitle("Joint model")

  multiplot(p1, p2, pj)
}
# }

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