terra (version 0.4-3)

rast: Create a SpatRaster

Description

Methods to create a SpatRaster. These objects can be created from scratch or from a file.

A SpatRaster represents a spatially referenced surface divided into three dimensional cells (rows, columns, and layers).

When a SpatRaster is created from a file, it does (initially) not contain any cell (pixel) values in memory (RAM), it only has the parameters that describe the SpatRaster. You can access cell-values with values.

Usage

# S4 method for character
rast(x, ...)
# S4 method for missing
rast(x, nrows=180, ncols=360, nlyrs=1, xmin=-180, xmax=180, 
                                      ymin=-90, ymax=90, crs, extent, resolution, ...)
# S4 method for SpatRaster
rast(x, nlyrs=nlyr(x), ...) 
# S4 method for matrix
rast(x, crs=NA, type="", ...)
# S4 method for SpatVector
rast(x, nrows=10, ncols=10, nlyrs=1, ...)
									  
# S4 method for SpatExtent
rast(x, nrows=10, ncols=10, nlyrs=1, crs="", ...)
# S4 method for Raster
rast(x, ...)

Arguments

x

filename (character), Extent, SpatRaster, matrix, array, or Raster* object (from the "raster" package). Can also be missing

nrows

positive integer. Number of rows

ncols

positive integer. Number of columns

nlyrs

positive integer. Number of layers

xmin

minimum x coordinate (left border)

xmax

maximum x coordinate (right border)

ymin

minimum y coordinate (bottom border)

ymax

maximum y coordinate (top border)

extent

object of class SpatExtent. If present, the arguments xmin, xmax, ymin and ymax are ignored

crs

character. PROJ.4 type description of a Coordinate Reference System (map projection). If this argument is missing, and the x coordinates are within -360 .. 360 and the y coordinates are within -90 .. 90, "+proj=longlat +datum=WGS84" is used

resolution

numeric vector of length 1 or 2 to set the resolution (see res). If this argument is used, arguments ncol and nrow are ignored

type

character. If the value is not "xyz", the raster has the same number of rows and colums as the matrix. If the value is "xyz", the matrix must have at least two columns, the first with x (or longitude) and the second with y (or latitude) coordinates that represent the centers of raster cells. The additional columns are the values associated with the raster cells.

...

additional arguments. None implemented

Value

SpatRaster

Examples

# NOT RUN {
# Create a SpatRaster from scratch
x <- rast(nrow=108, ncol=21, xmin=0, xmax=10)

# Create a SpatRaster from a file
f <- system.file("exdata/test.tif", package="terra")
r <- rast(f)

s <- rast(system.file("exdata/logo.grd", package="terra"))   

# Create a skeleton with no associated cell values
rast(s)
# }