betaFun                 Beta response function
convertToPA             Convert a virtual species distribution (or a
                        suitability raster) into presence-absence
custnorm                Normal function defined by extremes
formatFunctions         Format and visualise functions used to generate
                        virtual species with 'generateSpFromFun'
generateRandomSp        Generate a random virtual species distribution
                        from environmental variables
generateSpFromBCA       Generate a virtual species distribution from a
                        Between Component Analysis of environmental
                        variables
generateSpFromFun       Generate a virtual species distributions with
                        responses to environmental variables
generateSpFromPCA       Generate a virtual species distribution with a
                        PCA of environmental variables
limitDistribution       Limit a virtual species distribution to a
                        defined area
linearFun               Linear function
logisticFun             Logistic function
plotResponse            Visualise the response of the virtual species
                        to environmental variables
plotSuitabilityToProba
                        Visualise the function that was used to
                        transform environmental suitability into
                        probability of occurrence
quadraticFun            Quadratic function
removeCollinearity      Remove collinearity among variables of a raster
                        stack
sampleOccurrences       Sample occurrences in a virtual species
                        distribution
synchroniseNA           Synchronise NA values among layers of a stack
