## ----raster-1a----------------------------------------------------------------
library(terra)
# SpatRaster with the default parameters
x <- rast()
x


## ----raster-1b----------------------------------------------------------------
x <- rast(ncol=36, nrow=18, xmin=-1000, xmax=1000, ymin=-100, ymax=900)


## ----raster-1c----------------------------------------------------------------
res(x)
res(x) <- 100
res(x)


## ----raster-1d----------------------------------------------------------------
ncol(x)
ncol(x) <- 18
ncol(x)
res(x)


## ----raster-1e----------------------------------------------------------------
crs(x) <- "+proj=utm +zone=48 +datum=WGS84"
x


## ----raster-1h----------------------------------------------------------------
r <- rast(ncol=10, nrow=10)
ncell(r)
hasValues(r)


## ----raster-1i----------------------------------------------------------------
values(r) <- 1:ncell(r)


## ----raster-1j, fig.width=9, fig.height=4-------------------------------------
set.seed(0)
values(r) <- runif(ncell(r))

hasValues(r)
sources(r)
values(r)[1:10]
plot(r, main='Raster with 100 cells')


## ----raster-1x----------------------------------------------------------------
hasValues(r)
res(r)
dim(r)
# extent
ext(r)


## ----raster-1y----------------------------------------------------------------
xmax(r) <- 0
hasValues(r)
res(r)
dim(r)


## ----raster-1z----------------------------------------------------------------
ncol(r) <- 6
hasValues(r)
res(r)
dim(r)
xmax(r)


## ----raster-2a1---------------------------------------------------------------
filename <- system.file("ex/elev.tif", package="terra")
basename(filename)


## ----raster-2a2---------------------------------------------------------------
r <- rast(filename)
sources(r)
hasValues(r)
plot(r, main="SpatRaster from file")


## ----raster-2b1---------------------------------------------------------------
r1 <- r2 <- r3 <- rast(nrow=10, ncol=10)
# Assign random cell values 
values(r1) <- runif(ncell(r1))
values(r2) <- runif(ncell(r2))
values(r3) <- runif(ncell(r3))


## ----raster-2b2---------------------------------------------------------------
s <- c(r1, r2, r3)
s
nlyr(s)


## ----raster-2b5---------------------------------------------------------------
filename <- system.file("ex/logo.tif", package="terra")
basename(filename)
b <- rast(filename)
b
nlyr(b)


## ----raster-2b6---------------------------------------------------------------
r <- b[[2]]


## ----raster-3a1---------------------------------------------------------------
r <- rast(ncol=10, nrow=10)
values(r) <- 1:ncell(r)


## ----raster-3a2---------------------------------------------------------------
s <- r + 10
s <- sqrt(s)
s <- s * r + 5
values(r) <- runif(ncell(r))
r <- round(r)
r <- r == 1


## ----raster-3b----------------------------------------------------------------
#Not yet implemented
s[r] <- -0.5
s[!r] <- 5
s[s == 5] <- 15


## ----raster-3c----------------------------------------------------------------
r <- rast(ncol=5, nrow=5)
values(r) <- 1
s <- c(r, r+1)
q <- c(r, r+2, r+4, r+6)
x <- r + s + q
x


## ----raster-3d----------------------------------------------------------------
a <- mean(r,s,10)
b <- sum(r,s)
st <- c(r, s, a, b)
sst <- sum(st)
sst


## ----raster-3e----------------------------------------------------------------
global(st, 'sum')
global(sst, 'sum')


## ----raster-5, fig.width=9, fig.height=4--------------------------------------
r <- rast()
values(r) <- 1:ncell(r)
ra <- aggregate(r, 20)
rd <- disagg(ra, 20)


## ----raster-5b, fig.width=9, fig.height=4-------------------------------------
r1 <- crop(r, ext(-50,0,0,30))
r2 <- crop(r, ext(-10,50,-20, 10))
m <- merge(r1, r2, filename="test.tif", overwrite=TRUE)
plot(m)


## ----echo=FALSE, include=FALSE------------------------------------------------
ff <- list.files(patt="^test")
file.remove(ff)


## ----raster-6a----------------------------------------------------------------
r <- rast(ncol=3, nrow=2)
values(r) <- 1:ncell(r)
values(r)


## ----raster-6b----------------------------------------------------------------
s <- app(r, fun=function(x){ x[x < 4] <- NA; return(x)} )
as.matrix(s)


## ----raster-6c----------------------------------------------------------------
rs <- c(r, s)
w <- lapp(rs, fun=function(x, y){ x / (2 * sqrt(y)) + 5 } )
as.matrix(w)


## ----raster-6d----------------------------------------------------------------
u <- mask(r, w)
as.matrix(u)


## ----raster-6e----------------------------------------------------------------
v <- u==s
as.matrix(v)


## ----raster-6f----------------------------------------------------------------
cvr <- cover(w, r)
as.matrix(w)


## ----raster-6g----------------------------------------------------------------
x <- classify(w, rbind(c(0,2,1),  c(2,5,2), c(4,10,3)))
as.matrix(x)


## ----raster-6h----------------------------------------------------------------
y <- classify(x, cbind(id=c(2,3), v=c(40,50)))
as.matrix(y)


## ----raster-7-----------------------------------------------------------------
r <- rast(nrow=45, ncol=90)
values(r) <- round(runif(ncell(r))*3)
a <- cellSize(r)
zonal(a, r, "sum")


## ----raster-10a---------------------------------------------------------------
r <- rast(ncol=36, nrow=18)
values(r) <- runif(ncell(r))
global(r, mean)


## ----raster-10b---------------------------------------------------------------
s <- r
values(s) <- round(runif(ncell(r)) * 5)
zonal(r, s, 'mean')


## ----raster-10c---------------------------------------------------------------
freq(s)
freq(s, value=3)


## ----raster-10d---------------------------------------------------------------
ctb <- crosstab(c(r*3, s))
head(ctb)


## ----raster-15----------------------------------------------------------------
r <- rast(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, cbind(0,0))
colFromX(r, 0)
rowFromY(r, 0)


## ----raster-20----------------------------------------------------------------
r <- rast(system.file("ex/elev.tif", package="terra"))
v <- values(r)
v[3075:3080, ]
values(r, row=33, nrow=1, col=35, ncol=6)


## ----raster-21----------------------------------------------------------------
cells <- cellFromRowCol(r, 33, 35:40)
cells
r[cells]
xy <- xyFromCell(r, cells)
xy
extract(r, xy)


## ----raster-32----------------------------------------------------------------
r[cells] 
r[1:4]
sources(r)
r[2:5] <- 10
r[1:4]
sources(r)


## ----raster-33----------------------------------------------------------------
r[1:3]
r[1,1:3]
r[1, 1:5]
r[1:5, 2]
r[1:3,1:3]

# get a vector instead of a a matrix
r[1:3, 1:3, drop=TRUE]

# or a raster like matrix 
as.matrix(r, wide=TRUE)[1:3, 1:4]


## ----raster-120---------------------------------------------------------------
r <- rast(ncol=36, nrow=18)
values(r) <- runif(ncell(r))
library(raster)
x <- raster(r)