If x is a Spatial or an Extent object, additional arguments are for the method with signature 'missing' Value If the ncdf file does not have a standard extension (which is used to recognize the file format), you can use argument ncdf=TRUE to indicate the format. It is assumed that these files follow, or are compatible with, the CF-1 convention (The GMT format may also work). To use NetCDF files the ncdf4 package needs to be available. to create a RasterBrick of weather over time at a certain height. To select the 'level' (4th dimension variable) to use, if the file has 4 dimensions, e.g. To select the 'level variable' (3rd dimension variable) to use, if the file has 4 dimensions (e.g. If not supplied and the file has multiple variables are a guess will be made (and reported) The variable name, such as 'tasmax' or 'pr'. If x represents a NetCDF file, the following additional variable is recognized: Ignored when the file provides a CRS description that can be interpreted. To indicate the number of header rows on non-standard ascii files (rarely useful use with caution)Ĭrs: character. The default is TRUE, in which case a raster attribute table is created for files that have one 'raster' and netcdf format files are always read with native drivers. If TRUE, reading and writing of IDRISI, BIL, BSQ, BIP, SAGA, and Arc ASCII files is done with native (raster package) drivers, rather then via GDAL. Subdataset number for a file with subdatasets If x is a filename, the following additional variables are recognized: If not NULL, arguments xmn, xmx, ymn, ymx and crs (unless template is an Extent object) are ignored Raster* or Extent object used to set the extent (and CRS in case of a Raster* object). If this argument is used, arguments ncols and nrows are ignored Numeric vector of length 1 or 2 to set the resolution (see res). Also see under Details if x is a character (filename) 90, "+proj=longlat +datum=WGS84" is used. 360 and the y coordinates are within -90. If this argument is missing, and the x coordinates are within -360. PROJ.4 type description of a Coordinate Reference System (map projection). If present, the arguments xmn, xmx, ymn and ynx are ignoredĬharacter or object of class CRS. If TRUE, the cell values of ' x' are copied to the RasterLayer object that is returned An empty RasterLayer (no associated values) is returned if layer=0 The layer (variable) to use in a multi-layer file, or the layer to extract from a RasterStack/Brick or SpatialPixelsDataFrame or SpatialGridDataFrame. Supported file types are the 'native' raster package format and those that can be read by GDAL # S4 method for signature 'SpatialPixels'įilename (character), Extent, Raster*, sf, SpatialPixels*, SpatialGrid*, object, 'image', matrix, im, or missing. Usage # S4 method for signature 'character' You can assign new values with setValues and with replacement.įor an overview of the functions in the raster package have a look here: raster-package. You can access cell-values with getValues, extract and related functions. when a RasterLayer is created from a file, it does (initially) not contain any cell (pixel) values in (RAM) memory, it only has the parameters that describe the RasterLayer. RasterLayer objects can be created from scratch, a file, an Extent object, a matrix, an 'image' object, or from a Raster*, Spatial*, im (spatstat) asc, kasc (adehabitat*), grf (geoR) or kde object. dimensions: Dimensions of a Raster* object.datasource: Are values in memory and/or on disk?.cover: Replace NA values with values of other layers.corLocal: Local correlation coefficient.coords: Coordinates of the Extent of a Raster object.Compare-methods: Compare Raster* objects.compareCRS: Partially compare two CRS objects. cellsFromExtent: Cells from extent, and vice versa.cellFrom: Get cell, row, or column number.boundaries: boundaries (edges) detection.blockSize: Block size for writing files.as.matrix: Get a vector, matrix, or array with raster cell values.as.logical-methods: Change cell values to logical or integer values.as.list: Create a list of RasterLayer objects.as.ame: Get a ame with raster cell values, or coerce.as.character: Character representation of a Raster or Extent object.Arith-methods: Arithmetic with Raster* objects.approxNA: Estimate values for cell values that are 'NA' by.animate: Animate layers of a Raster* object.alignExtent: Align an extent (object of class Extent).aggregate: Aggregate raster cells or SpatialPolygons/Lines.
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