grid_diversity: Function to grid geolocated, taxonomically-defined...
In MarineEcosystemResearchProgramme/merpData: Mapping and enriching of marine data

Description Usage Arguments Value Examples

Data portals such as OBIS typically return tables of geolocated observations upon requests. When combined with packages such as taxizesoap the taxonomy of all occurring species can be added. From there a common task is to map the number of unique species/genus/family (or other taxonomic group) on a lattice.

1 2	grid_diversity(mydata, taxonomic_level, myresolution = 0.5, myzoom = 7, lat_centre = NULL, lon_centre = NULL)

`mydata`	is an R data.frame. It must contain at least two columns containing latitudes and longitudes for each observation. `grid_diversity` will attempt to find in mydata the columns that contain that information. Column names must contain the letters "lat" and "lon".
`taxonomic_level`	is the taxonomic resolution for gridding. Possible choices are kingdom, phylum, class, order, family, genus and species
`myresolution`	is the size of the cells the data is to be aggregated over
`myzoom`	is the zoom to be applied to plot the gridded data on ggmap map
`lat_centre`	is the user-defined latitude the map will be centred on. Default to mean latitude of observations.
`lon_centre`	is the user-defined longitude the map will be centred on. Default to mean longitude of observations.

grid_diversity returns a data frame containing the number of unique taxonomic group per cell. The taxonomic resolution is defined by the user.

library(robis)
library(ggmap)
mydata <- occurrence(geometry = "POLYGON ((0 0, 0 45, 45 45, 45 0, 0 0))", year = 1975)
grid_diversity(mydata, taxonomic_level = "genus", myresolution = 2, myzoom = 3)
head(justchecking$gridded_data)
# plot the data
justchecking$myplot