fasterRaster (version 8.4.0.5)

runifRast,GRaster-method: Create a raster with random values drawn from a uniform distribution

Description

runifRast() creates a raster with values drawn from a uniform (flat) distribution.

Usage

# S4 method for GRaster
runifRast(x, n = 1, low = 0, high = 1, seed = NULL)

Value

A GRaster.

Arguments

x

A GRaster. The output will have the same extent and dimensions as this raster.

n

A numeric integer: Number of rasters to generate.

low, high

Numeric: Minimum and maximum values from which to select.

seed

Numeric integer vector or NULL: Random seed. If NULL, then a different seed will be generated by GRASS. Defining this is useful if you want to recreate rasters. If provided, there should be one seed value per raster.

See Also

rnormRast(), rSpatialDepRast(), fractalRast(), GRASS manual page for module r.random.surface (see grassHelp("r.random.surface"))

Examples

if (grassStarted()) {

# Setup
library(sf)
library(terra)

# Elevation raster
madElev <- fastData("madElev")

# Convert a SpatRaster to a GRaster:
elev <- fast(madElev)

### Create a raster with values drawn from a uniform distribution:
unif <- runifRast(elev)
plot(unif)

### Create a raster with values drawn from a normal distribution:
norms <- rnormRast(elev, n = 2, mu = c(5, 10), sigma = c(2, 1))
plot(norms)
hist(norms, bins = 100)

# Create a raster with random, seemingly normally-distributed values:
rand <- rSpatialDepRast(elev, dist = 1000)
plot(rand)

# Values appear normal on first inspection:
hist(rand)

# ... but actually are patterned:
hist(rand, bins = 100)

# Create a fractal raster:
fractal <- fractalRast(elev, n = 2, dimension = c(2.1, 2.8))
plot(fractal)
hist(fractal)

}