Rather than request a map of 'Switzerland' from google, you should request a map of a specific location by specifying a longitude/latitude and desired zoom (and maybe scale). Then you won't have to use coord_map()
and blur your image.
Here are the basics, you can play around with colors and sizes as in any ggplot:
library(ggplot2)
library(ggmap)
# copying text off screen
# since the OP did not use dput()
data<-read.table("clipboard")
# reformat
data=data[,-1]
names(data)=c("lon","lat","id")
data$lon <- as.numeric(gsub('[\\(\\)\\,]', '', data$lon))
data$lat <- as.numeric(gsub('[\\(\\)\\,]', '', data$lat))
head(data)
# lon lat id
# 1 7.17350 45.8688 2
# 2 7.17254 45.8689 3
# 3 7.17164 45.8692 4
# etc
# determine a reasonable center for map,
# this could fail in some places (near poles, 180th meridian)
# also google appears to shift things slightly
center = paste(min(data$lat)+(max(data$lat)-min(data$lat))/2,
min(data$lon)+(max(data$lon)-min(data$lon))/2, sep=" ")
# get map image from google
map <- get_map(location = center, zoom = 11, maptype = "terrain",
source = "google")
# start a ggplot. it won't plot til we type p
p <- ggmap(map)
# add text labels, these will overlap
p <- p + geom_text(data=data,aes(x = lon, y = lat,
label = id),
colour="white",size=4,hjust=0, vjust=0)+
theme(legend.position = "none")
# add points last so they are on top
p <- p + geom_point(data=data,aes(x=lon, y=lat),colour="white",size=2)
# display plot
p
This naturally is described in ?get_map
and ?get_googlemap
.