raster_runif: a raster with random values between 0 and 1 for every cell of the datasource GRTSmaster_habitats (Q6717964)

The raster_runifdata source covers the Flanders and Brussels region and has a resolution of 32 meters. The raster cells with non-missing values match the value-cells of the GRTSmaster_habitats data source with a small buffer added. Every raster cell has a random value between 0 and 1 according to the uniform distribution. An example usage of this raster is its combination with theGRTSmaster_habitatsandhabitatmap_stdized data sources in order to draw an equal probability sample of habitat types in Flanders.Habitatmap_stdizedcontains polygons that are partially or fully covered by habitat types. The proportion of a certain type within a polygon is provided by the phabvalue. We can draw anequal probability samplesizenfor a certain habitat type as follows: select all raster cells of GRTSmaster_habitats that overlap with the sampling frame of the target habitat type keep the raster cells for which the raster_runif value is lower than the phab value of the habitat type within the polygon finally select thenraster cells with the lowest GRTS ranking number. The R-code for creating theraster_runifdata source can be found in the GitHub repositoryn2khab-preprocessingat commitede43a4. A reading function to return the data source in a standardized way into the R environmentis provided by the R-packagen2khab.