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

Maybe this is a slightly simpler solution

library(dplyr)
library(ggplot2)

# fortify the shape file
  map.df <- fortify(shape, region ="CD_GEOCODI")

# merge data
  map.df <- left_join(map.df, data, by=c('id'='CD_GEOCODI'))