Copmute a raster with the importance of the nearest network node.

# S4 method for geonetwork,Raster
rasterize(x, y, field = "importance", ...)

# S4 method for geonetwork,SpatialPolygons
rasterize(x, y, res = resolution(y, max_ncells = 100), ...)

## Arguments

x a geographic network (a geonetwork object with node attributes "Lon" and "Lat" in the WGS84 reference system) a Raster* or a SpatialPolygons* object. character. The attribute of the network nodes to be assigned to the voronoi polygon associated with each node. By default it computes the importance of each node in the network. But you can manually compute any other measure of interest, and pass it as a vertex attribute (see ?igraph::vertex_attr<-). Other arguments passed on to rasterize. numeric vector of length 2. Resolution in Lon/Lat of rasterisation.

## Details

This assumes that the network object has node attributes "Lon" "Lat" in the WGS84 reference system.

If the graph is weighted, the weighted importance will be computed. If you want the unweighted importance, remove the weight attribute from the graph with igraph::delete_edge_attr(x, "weight").

The importance of each node is computed as the relative contribution to the Potential for Transmision $$R_0$$ of the graph. I.e., $$R_{0k}/R_0$$. See epidemic_threshold.