Inset graphics with rasterVis and grid

inset.R

library(raster)
library(rasterVis)
library(grid)
r <- raster(system.file("external/test.grd", package="raster"))

## Main graphic
p1 <- levelplot(r)
## Inset graphic
p2 <- levelplot(r,
                margin = FALSE,
                colorkey = FALSE,
                scales = list(draw = FALSE),
                par.settings = GrTheme)

## Create viewports (more info in https://stat.ethz.ch/R-manual/R-devel/library/grid/doc/grid.pdf)
## Main viewport
vp1 <- viewport()
pushViewport(vp1)
print(p1, newpage = FALSE)
## Inset viewport
xi <- 0.3
yi <- 0.6
wi <- 0.3
hi <- 0.2
vp2 <- viewport(x = xi,
                y = yi,
                height = hi,
                width = wi)
pushViewport(vp2)
print(p2, newpage=FALSE)