How keep information from shapefile after fortify()

Question

How can I keep polygons\'s information after shapefile? Let me try to explain:

I have a shapefile with this data:

> head(mapa@data)
         ID      C         


        

Answer 1

I came across the same problem and was able to achieve the desired results using slightly different approach.

Import and fortify

I have used the following code to read the shapes:

shps <- maptools::readShapePoly(fn = file.path("file",
                                               "path",
                                               "no extension"),
                                     # Column with unique IDs
                                     IDvar = "geoID")

and subsequently fortified the objet using the code:

shpsFort <- ggplot2::fortify(model = shps)

Results

This created a data.frame object with the id value corresponding to the column passed in IDvar = "geoID". Adding any other data could be simply addressed via ordinary merge command.