Raster prueba

Introduccion

Configuracion de libreria

# NUEVO CUADERNO 
library(terra)

## Warning: package 'terra' was built under R version 4.2.3

## terra 1.7.71

Creación de raster desde Cero

# Creacion de raster desde cero
r <- rast(nrows=40, ncols=20, xmin=0, xmax=10, ymin=0, ymax=10)
r

## class       : SpatRaster 
## dimensions  : 40, 20, 1  (nrow, ncol, nlyr)
## resolution  : 0.5, 0.25  (x, y)
## extent      : 0, 10, 0, 10  (xmin, xmax, ymin, ymax)
## coord. ref. : lon/lat WGS 84

values(r) <- runif(ncell(r))

v <- values(r)
dim(v)

## [1] 800   1

head(v)

##          lyr.1
## [1,] 0.8764688
## [2,] 0.8028081
## [3,] 0.5854401
## [4,] 0.9149462
## [5,] 0.5530419
## [6,] 0.3709626

plot(r)

MANIPULACION SpatRaster

#MANIPULAR SpatRaster
q <- 100 * r^2
plot(q)

# create a binary mask based on a logical expression
m <- q < 10 
plot(m)

p <- c(r, q)

# assign meaningful names to the layers
names(p) <- c ("random", "scaled_random")

plot(p)

ma <- mean(p)
plot(ma)

global(p, fun="mean")

##                     mean
## random         0.5045257
## scaled_random 33.8800103

r[r < 0.5] <-0.5
plot(r, range=c(0,1))

myFunction <-function(x){x[x <=0.5] <- 10; return(x)}
w <- app(r, fun=myFunction)
plot(w, range=c(0,1))