## ----raster-15----------------------------------------------------------------
library(raster)
r <- raster(ncol=36, nrow=18)
ncol(r)
nrow(r)
ncell(r)
rowFromCell(r, 100)
colFromCell(r, 100)
cellFromRowCol(r,5,5)
xyFromCell(r, 100)
cellFromXY(r, c(0,0))
colFromX(r, 0)
rowFromY(r, 0)


## ----raster-20----------------------------------------------------------------
r <- raster(system.file("external/test.grd", package="raster"))
v <- getValues(r, 50)
v[35:39]
getValuesBlock(r, 50, 1, 35, 5)


## ----raster-21----------------------------------------------------------------
cells <- cellFromRowCol(r, 50, 35:39)
cells
extract(r, cells)
xy <- xyFromCell(r, cells)
xy
extract(r, xy)


## ----raster-32----------------------------------------------------------------
r[cells] 
r[1:4]
filename(r)
r[2:3] <- 10
r[1:4]
filename(r)


## ----raster-33----------------------------------------------------------------
r[1]
r[2,2]
r[1,]
r[,2]
r[1:3,1:3]

# keep the matrix structure
r[1:3,1:3, drop=FALSE]