species.richness.main 		The main function to estimate or cross-validate the species richness based on given species occurences.
species.richness 			Estimates the species richness based on given species occurences.
species.richness.cv			Cross-validates the species richness based on given species occurences.
species.range				Estimates the species range based on given occurences of one species.
extract.species 			Extracts the datasets of one species out of a database filled with species and their occurence locations.
getDimension				Calculates the dimension of the grid which should be used for a species richness estimation.
getShift				Calculates the origin of the grid used for a species richness estimation.
getDistance				Calculates the distance of two points in a grid.
add.Data.to.Grid			Adds the species occurence data to the grid.
add.Edges				Adds an edge between two points to a grid.
edgeNotValid				Checks if an edge would cross a water or mountain surface.
fill.Areas				Fills all bounded areas in a grid.
createLandwatermask			Creates a land-water-mask as a grid based on given dimension and coordinates.
createHeightmask			Creates a height-mask as a grid based on given dimension and coordinates.
generate.subsamples			Creates an array of subsamples of a dataset.
createImage				Creates a levelplot of the result-grid of species range estimation and saves it as a PNG-File.
evaluate 				Evaluates the result grids of species richness estimation and creates a PNG-File with histogramm and statistic information.
exportAsGDAL				Exports the result grid as a GDAL grid map.
createNonInterpolatedGrid		Creates a grid containing the species occurences.
adjustment				Adjusts the weighted species richness for sampling effort.
searchClusters			Searches clusters in the result grid of species richness estimation.
