Multi panel plot

Map_Hist.R

library(sp)
library(rgeos)
library(rworldmap)


# epsg.io
wgs=CRS("+init=epsg:4326")

map_dat=getMap()
map_dat=spTransform(map_dat,wgs)

# fake data
set.seed(123)
foo.dat=data.frame(long=runif(150,-100,180),
           lat=runif(150,-90,100),
           val=rnorm(150,200,150))
foo.dat.shp=SpatialPointsDataFrame(foo.dat[,c("long","lat")],
                                   data=foo.dat,
                                   proj4string = wgs)


par(oma=c(0.5,0.5,0.5,0.5),mar=c(2,2,0.5,0.5))
layout(matrix(1:2,1,2),widths=c(1,0.5))
plot(map_dat,xlim=c(-180,180),ylim=c(-90,90),bg="lightblue",col="cornsilk",yaxs="i",xaxs="i")
plot(foo.dat.shp,add=T,pch=21,bg="red")
box(lwd=1)

# aggregate data into Latitude bins
bks.val=seq(-90,90,20)
lat.bin=findInterval(foo.dat$lat,bks.val)
foo.dat$lat.bin=bks.val[lat.bin]
mean.val=aggregate(val~lat.bin,foo.dat,mean)

#pseudo histogram
x=barplot(mean.val$val,horiz = T,space=0,xlim=c(0,400))
axis(2,x,bks.val,las=2)
box(lwd=1)