To figure out the correct variable name for region, inspect as.data.frame(model).

# S3 method for SpatialPolygonsDataFrame
fortify(model, data, region = NULL, ...)

# S3 method for SpatialPolygons
fortify(model, data, ...)

# S3 method for Polygons
fortify(model, data, ...)

# S3 method for Polygon
fortify(model, data, ...)

# S3 method for SpatialLinesDataFrame
fortify(model, data, ...)

# S3 method for Lines
fortify(model, data, ...)

# S3 method for Line
fortify(model, data, ...)

Arguments

model

SpatialPolygonsDataFrame to convert into a dataframe.

data

not used by this method

region

name of variable used to split up regions

...

not used by this method

Examples

if (require("maptools")) { sids <- system.file("shapes/sids.shp", package="maptools") nc1 <- readShapePoly(sids, proj4string = CRS("+proj=longlat +datum=NAD27")) nc1_df <- fortify(nc1) }
#> Loading required package: maptools
#> Loading required package: sp
#> Checking rgeos availability: TRUE
#> Regions defined for each Polygons