biomod2 (version 3.5.1)

evaluate: biomod2 modelling outputs evaluation

Description

This function will evaluate biomod2 modelling output for given metrics (e.g 'TSS', 'ROC'...) for a given dataset.

Usage

evaluate(model, data, stat, as.array=FALSE)

Value

a list or an array containing for each evaluation metric the score, the threshold considered to transform continuous data into binary ones (for all metrics excepted 'ROC') and associated sensibility and specificity.

Arguments

model

the model you want evaluate (either "BIOMOD.models.out", "BIOMOD.EnsembleModeling.out" or "biomod2_model" )

data

the data.set on which you want to perform analyses. Must be a dataset with first column containing the observed data for your species. The flowing columns must be the explanatory variables at observed points. Be sure that columns names of your dataset are the name of your species then the names of variables used for building models at previous steps.

stat

vector of statistic metrics names (e.g 'TSS','ROC') you want to perform. (see BIOMOD_Modeling) to get the list of all available metrics)

as.array

logical, (FALSE by default) if FALSE a list of evaluation tables is returned (one item by models). If TRUE, the output will be return under 'classical' biomod2 array objects (see BIOMOD_Projection)

Author

Damien Georges

Details

Given model predictive score is evaluated on the new data set. It is done comparing binary transformed model predictions (on data set) to species occurrences (first column of data arg). A list of available evaluation metrics is given in BIOMOD_Modeling help file. For metrics that compared binary/binary data, a set of threshold will be test to transform continuous model prediction within binary ones. The return scores are the ones obtained for the threshold optimizing tested metric (best score).

See Also

BIOMOD_Modeling, BIOMOD_EnsembleModeling, variables_importance

Examples

# species occurrences
DataSpecies <- read.csv(system.file("external/species/mammals_table.csv",
                                    package="biomod2"), row.names = 1)
head(DataSpecies)

# the name of studied species
myRespName <- 'GuloGulo'

# the presence/absences data for our species 
myResp <- as.numeric(DataSpecies[,myRespName])

# the XY coordinates of species data
myRespXY <- DataSpecies[,c("X_WGS84","Y_WGS84")]


# Environmental variables extracted from BIOCLIM (bio_3, bio_4, bio_7, bio_11 & bio_12)
myExpl = raster::stack( system.file( "external/bioclim/current/bio3.grd", 
                     package="biomod2"),
                system.file( "external/bioclim/current/bio4.grd", 
                             package="biomod2"), 
                system.file( "external/bioclim/current/bio7.grd", 
                             package="biomod2"),  
                system.file( "external/bioclim/current/bio11.grd", 
                             package="biomod2"), 
                system.file( "external/bioclim/current/bio12.grd", 
                             package="biomod2"))

# 1. Formatting Data
myBiomodData <- BIOMOD_FormatingData(resp.var = myResp,
                                     expl.var = myExpl,
                                     resp.xy = myRespXY,
                                     resp.name = myRespName)

# 2. Defining Models Options using default options.
myBiomodOption <- BIOMOD_ModelingOptions()

# 3. Doing Modelisation

myBiomodModelOut <- BIOMOD_Modeling( myBiomodData, 
                                     models = c('SRE','CTA','RF'), 
                                     models.options = myBiomodOption, 
                                     NbRunEval=1, 
                                     DataSplit=80, 
                                     Yweights=NULL, 
                                     VarImport=3, 
                                     models.eval.meth = c('TSS'),
                                     SaveObj = TRUE,
                                     rescal.all.models = FALSE,
                                     do.full.models = FALSE,
                                     modeling.id='test')
                                     
# 4. Evaluate model over another dataset (here the full one)

## creation of suitable dataset
data <- cbind(GuloGulo=get_formal_data(myBiomodModelOut,'resp.var'), 
              get_formal_data(myBiomodModelOut,'expl.var'))

## evaluation
evaluate(myBiomodModelOut, data=data, stat=c('ROC','TSS'))