## S4 method for signature 'formula,Raster'
xyplot(x, data, dirXY, maxpixels=1e5,
            alpha=0.05,
            xscale.components=xscale.raster, yscale.components=yscale.raster,
            par.settings=rasterTheme(),...)
## S4 method for signature 'formula,Raster'
hexbinplot(x, data, dirXY, maxpixels=1e6,
            xscale.components=xscale.raster, yscale.components=yscale.raster,
            par.settings=rasterTheme(),...)
## S4 method for signature 'formula,SpatRaster'
xyplot(x, data, dirXY, maxpixels=1e5,
            alpha=0.05,
            xscale.components=xscale.raster, yscale.components=yscale.raster,
            par.settings=rasterTheme(),...)
## S4 method for signature 'formula,SpatRaster'
hexbinplot(x, data, dirXY, maxpixels=1e6,
            xscale.components=xscale.raster, yscale.components=yscale.raster,
            par.settings=rasterTheme(),...)

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

xyplot(test~y, data=r, alpha=0.5)

## Not run: 
dataURL <- "https://raw.github.com/oscarperpinan/bookvis/master/data/"

##Solar irradiation data from CMSAF http://dx.doi.org/10.5676/EUM_SAF_CM/RAD_MVIRI/V001
old <- setwd(tempdir())
download.file(paste0(dataURL, "SISmm2008_CMSAF.zip"),
   "SISmm2008_CMSAF.zip", method='wget')
unzip("SISmm2008_CMSAF.zip")

listFich <- dir(pattern='\\.nc')
stackSIS <- stack(listFich)
SISmm <- stackSIS*24 ##from irradiance (W/m2) to irradiation Wh/m2
setwd(old)

names(SISmm) <- month.abb

##Relation between the January & February versus July radiation for four
##differents longitude regions.
xyplot(Jan+Feb~Jul|cut(x, 4), data=SISmm, auto.key=list(space='right'))
##Faster with hexbinplot
hexbinplot(Jan~Jul|cut(x, 6), data=SISmm)

## End(Not run)