R：在screen（）内绘制光栅图像不起作用

Question

I am trying to plot a rasterLayer object on a plot composed of two figures using screen

First - a working case scenario when we only have one image:

library(raster)
f <- system.file("external/test.grd", package="raster")
rst <- raster(f)

plot(rst)
points(180000, 332000, col="red", pch=19)

Everything looks fine and the image looks like this:

However when I split the screen into two and try to plot the same figure using only half of the plotting region I get the following:

library(raster)
f <- system.file("external/test.grd", package="raster")
rst <- raster(f)
class(rst)

figs <- rbind(c(0, 0.5, 0, 1), # Screen1
              c(0.5, 1, 0, 1)  # Screen2
              )
screenIDs <- split.screen(figs)

screen(screenIDs[1])
plot(rst)
points(180000, 332000, col="red", pch=19)

It seems like the main image of the raster shape is being drawn correctly. However for some reason it then captures the entire plotting region and adds a boundary lines on it. After that subsequent calls to the plot (like points ) add points on the whole figure rather than staying in the first half of it.

Any ideas how to solve or bypass this are most appreciated.

Answer 1

You can use layout instead of split.screen . Demonstrated here, as in your example, with a simple layout of just 1 row of two equal-sized panels. For how to get more complex layouts, have a look at ?layout

layout(matrix(c(1,2), 1, 2, byrow = TRUE))
plot(rst)
points(180000, 332000, col="red", pch=19)

plot(1:10,1:10) # a dummy plot to put in the right hand panel