grid_data: Function to grid geolocated observations on a map
In remsamp/Rmerp_public:

Description Usage Arguments Value Examples

Data portals such as OBIS typically return tables of geolocated observations upon requests. Gridded data is often used to represent in a synthetic way this type of observations, but although R packages ggplot2 and ggmap are good at representing it, there is no built-in function to go from raw to aggregated data.

1 2	grid_data(lat, lon, myresolution = 0.5, myzoom = 7, lat_centre = NULL, lon_centre = NULL)

`lat`	is a numerical vector of latitudes for the set of observations.
`lon`	is a numerical vector of longitudes for the set of observations.
`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_data returns a data frame containing the number of observations per cell.

library(robis)
obs <- occurrence("Gadus morhua", year = 2002)
justchecking <- grid_data(lat = obs$decimalLatitude, lon = obs$decimalLongitude, myresolution = 0.5, myzoom = 4)
# examine the data
head(justchecking$gridded_data)
# plot the data
justchecking$myplot