I have 2 graphs, a map plotted with ggplot2 like this: 
w<-ggplot()+
  geom_polygon(data=dep_shp.df, aes(x=long,y=lat,group=group,fill=classJenks))+
  #   scale_fill_gradient(limits=c(40, 100))+
  labs(title ="Classification de la proportion de producteurs par départements
       \n par la methode de jenks (2008)")+
  theme_bw()+
  coord_equal()
and a graph as object of type classIntervals  from the classInt library.
I would like to put together this 2 graphs. I have tried:
vplayout <- function(x, y) viewport(layout.pos.row = x, layout.pos.col = y)
grid.newpage()
pushViewport(viewport(layout = grid.layout(1, 2)))
#creation
print(u, vp = vplayout(1, 1))
print(v, vp = vplayout(1, 2))
And something with grid.arrange
grid.arrange(plot1, plot2, ncol=2)
but none of these work.
 
     
    