# excProb: Exceedance probabilities In geostatsp: Geostatistical Modelling with Likelihood and Bayes

## Description

Calculate exceedance probabilities pr(X > threshold) from a fitted geostatistical model.

## Usage

 ```1 2``` ```excProb(x, threshold=0, random=FALSE, template=NULL, templateIdCol=NULL, nuggetInPrediction=TRUE) ```

## Arguments

 `x` Output from either the `lgm` or `glgm` functions, or a list of two-column matrices with columns named `x` and `y` containing the posterior distributions of random effects, as produced by `inla`. `threshold` the value which the exceedance probability is calculated with respect to. `random` Calculate exceedances for the random effects, rather than the predicted observations (including fixed effects). `template` A `Raster` or `SpatialPolygonsDataFrame` or `SpatialPointsDataFrame` object which the results will be contained in. `templateIdCol` The data column in `template` corresponding to names of `marginals` `nuggetInPrediction` If `TRUE`, calculate exceedance probabilities of new observations by adding the nugget effect. Otherwise calculate probabilities for the latent process. Ignored if `x` is output from `glgm`.

## Details

When `x` is the output from `lgm`, pr(Y>threshold) is calculated using the Gaussian distribution using the Kriging mean and conditional variance. When `x` is from the `glgm` function, the marginal posteriors are numerically integrated to obtain pr(X > threshold).

## Value

Either a vector of exceedance probabilities or an object of the same class as `template`.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19``` ``` data('swissRain') swissFit = lgm("rain", swissRain, grid=30, boxcox=0.5,fixBoxcox=TRUE, covariates=swissAltitude) swissExc = excProb(swissFit, 20) mycol = c("green","yellow","orange","red") mybreaks = c(0, 0.2, 0.8, 0.9, 1) plot(swissBorder) plot(swissExc, breaks=mybreaks, col=mycol,add=TRUE,legend=FALSE) plot(swissBorder, add=TRUE) legend("topleft",legend=mybreaks, col=c(NA,mycol)) ## Not run: swissRain\$sqrtrain = sqrt(swissRain\$rain) swissFit2 = glgm(formula="sqrtrain",data=swissRain, grid=40, covariates=swissAltitude,family="gaussian") swissExc = excProb(swissFit2, threshold=sqrt(30)) swissExc = excProb(swissFit2\$inla\$marginals.random\$space, 0, template=swissFit2\$raster) ## End(Not run) ```

geostatsp documentation built on Oct. 5, 2021, 9:10 a.m.