First, the map your are displaying does not run from long = [11.8,12.01]
; more like [11.8,17.01]
. But that's not your problem.
The problem is this: the plot method for SpatialPolygons fixes the aspect ratio so the map will not be distorted. So when you, say, expand the map vertically (make it taller), the map wants to get wider too, but can't. So it's clipped.
The ggplot
package manages this much more cleanly:
library(rgdal)
library(ggplot2)
setwd("<directory with map>")
greg=readOGR(dsn=".",layer="GREG")
yugo <- greg[greg$COW == 345,]
yugo.df <- fortify(yugo)
ggp <- ggplot(yugo.df)
ggp <- ggp + geom_path(aes(x=long,y=lat,group=group))
ggp <- ggp + coord_fixed()
ggp
ggp + xlim(11.8,17.01) + ylim(43.6,47)
Now try changing the size of the window that contains this map and see what happens.
EDIT [response to OP's comment]
Add this before rendering:
ggp <- ggp + theme_bw()
ggp <- ggp + theme(line = element_blank(),
text = element_blank(),
rect = element_blank())
ggp
You basically want to "turn off" all the default formatting. The call to theme_bw()
gives you a black/white color scheme. The calls to element_blank()
turn off lines, text, and the bounding rectangle.