brick {raster} | R Documentation

## Create a RasterBrick object

### Description

A RasterBrick is a multi-layer raster object. They are typically created from a multi-layer (band) file; but they can also exist entirely in memory. They are similar to a RasterStack (that can be created with `stack`), but processing time should be shorter when using a RasterBrick. Yet they are less flexible as they can only point to a single file.

A RasterBrick can be created from RasterLayer objects, from a RasterStack, or from a (multi-layer) file. The can also be created from SpatialPixels*, SpatialGrid*, and Extent objects, and from a three-dimensional array.

### Usage

    ## S4 method for signature 'character'
    brick(x, ...)

    ## S4 method for signature 'RasterStack'
    brick(x, values=TRUE, nl, filename='', ...)

    ## S4 method for signature 'RasterBrick'
    brick(x, nl, ...)

    ## S4 method for signature 'RasterLayer'
    brick(x, ..., values=TRUE, nl=1, filename='')

    ## S4 method for signature 'missing'
    brick(nrows=180, ncols=360, xmn=-180, xmx=180, ymn=-90, ymx=90, nl=1, crs)

    ## S4 method for signature 'Extent'
    brick(x, nrows=10, ncols=10, crs=NA, nl=1)

    ## S4 method for signature 'array'
    brick(x, xmn=0, xmx=1, ymn=0, ymx=1, crs=NA, transpose=FALSE)

    ## S4 method for signature 'big.matrix'
    brick(x, template, filename='', ...)

    ## S4 method for signature 'SpatialGrid'
    brick(x)

    ## S4 method for signature 'SpatialPixels'
    brick(x)

### Arguments

`x` | character (filename, see Details); Raster* object; missing; array; SpatialGrid*; SpatialPixels*; Extent; or list of Raster* objects. Supported file types are the 'native' raster package format and those that can be read via rgdal (see `readGDAL`), and NetCDF files (see details)
`...` | see Details
`values` | logical. If `TRUE`, the cell values of '`x`' are copied to the RasterBrick object that is returned
`nl` | integer > 0. How many layers should the RasterBrick have?
`filename` | character. Filename if you want the RasterBrick to be saved on disk
`nrows` | integer > 0. Number of rows
`ncols` | integer > 0. Number of columns
`xmn` | minimum x coordinate (left border)
`xmx` | maximum x coordinate (right border)
`ymn` | minimum y coordinate (bottom border)
`ymx` | maximum y coordinate (top border)
`crs` | character or object of class CRS. PROJ4 type description of a Coordinate Reference System (map projection). If this argument is missing, and the x coordinates are withing -360 .. 360 and the y coordinates are within -90 .. 90, "+proj=longlat +datum=WGS84" is used
`transpose` | if `TRUE`, the values in the array are transposed
`template` | Raster* object used to set the extent, number of rows and columns and CRS

### Details

If `x` is a RasterLayer, the additional arguments can be used to pass additional Raster* objects.

If there is a `filename` argument, the additional arguments are as for `writeRaster`. The big.matrix most have rows representing cells and columns representing layers.

If `x` represents a filename there is the following additional argument:

`native`: logical. If `TRUE` (not the default), reading and writing of IDRISI, BIL, BSQ, BIP, and Arc ASCII files is done with native (raster package) drivers, rather then via rgdal.

In addition, if `x` is a NetCDF filename there are the following additional arguments:

`varname`: character. The variable name (e.g. 'altitude' or 'precipitation'. If not supplied and the file has multiple variables are a guess will be made (and reported))

`lvar`: integer > 0 (default=3). To select the 'level variable' (3rd dimension variable) to use, if the file has 4 dimensions (e.g. depth instead of time)

`level`: integer > 0 (default=1). To select the 'level' (4th dimension variable) to use, if the file has 4 dimensions, e.g. to create a RasterBrick of weather over time at a certain height.

To use NetCDF files the `ncdf4` package needs to be available. It is assumed that these files follow, or are compatible with the CF-1 convention.

### Value

RasterBrick

### See Also

`raster`

### Examples

    b <- brick(system.file("external/rlogo.grd", package="raster"))
    b
    nlayers(b)
    names(b)
    extract(b, 870)

[Package raster version 2.5-2 Index]