spatial.pred.poisson.MCML {PrevMap}

Spatial predictions for the Poisson model with log link function, using plug-in of MCML estimates

Description

This function performs spatial prediction, fixing the model parameters at the Monte Carlo maximum likelihood estimates of a geostatistical Poisson model with log link function.

Usage

spatial.pred.poisson.MCML(
  object,
  grid.pred,
  predictors = NULL,
  control.mcmc,
  type = "marginal",
  scale.predictions = c("log", "exponential"),
  quantiles = c(0.025, 0.975),
  standard.errors = FALSE,
  thresholds = NULL,
  scale.thresholds = NULL,
  plot.correlogram = FALSE,
  messages = TRUE
)

Arguments

object

an object of class "PrevMap" obtained as result of a call to poisson.log.MCML.

grid.pred

a matrix of prediction locations.

predictors

a data frame of the values of the explanatory variables at each of the locations in grid.pred; each column correspond to a variable and each row to a location. Warning: the names of the columns in the data frame must match those in the data used to fit the model. Default is predictors=NULL for models with only an intercept.

control.mcmc

output from control.mcmc.MCML.

type

a character indicating the type of spatial predictions: type="marginal" for marginal predictions or type="joint" for joint predictions. Default is type="marginal". In the case of a low-rank approximation only joint predictions are available.

scale.predictions

a character vector of maximum length 2, indicating the required scale on which spatial prediction is carried out: "log" and "exponential". Default is scale.predictions=c("log","exponential").

quantiles

a vector of quantiles used to summarise the spatial predictions.

standard.errors

logical; if standard.errors=TRUE, then standard errors for each scale.predictions are returned. Default is standard.errors=FALSE.

thresholds

a vector of exceedance thresholds; default is thresholds=NULL.

scale.thresholds

a character value indicating the scale on which exceedance thresholds are provided; "log" or "exponential". Default is scale.thresholds=NULL.

plot.correlogram

logical; if plot.correlogram=TRUE the autocorrelation plot of the conditional simulations is displayed.

messages

logical; if messages=TRUE then status messages are printed on the screen (or output device) while the function is running. Default is messages=TRUE.

Value

A "pred.PrevMap" object list with the following components: log; exponential; exceedance.prob, corresponding to a matrix of the exceedance probabilities where each column corresponds to a specified value in thresholds; samples, corresponding to a matrix of the predictive samples at each prediction locations for the linear predictor of the Poisson model (if scale.predictions="log" this component is NULL); grid.pred prediction locations. Each of the three components log and exponential is also a list with the following components:

predictions: a vector of the predictive mean for the associated quantity (log or exponential).

standard.errors: a vector of prediction standard errors (if standard.errors=TRUE).

quantiles: a matrix of quantiles of the resulting predictions with each column corresponding to a quantile specified through the argument quantiles.

Author(s)

Emanuele Giorgi [e-mail]

Peter J. Diggle [e-mail]