values: Cell values and geometry attributes

In terra: Spatial Data Analysis

Cell values and geometry attributes

Description

Get the cell values of a SpatRaster or the attributes of a SpatVector.

By default all values returned are numeric. This is because a vector or matrix can only store one data type, and a SpatRaster may consist of multiple data types. However, if all layers have integer or logical values, the returned values also have that datatype.

Note that with values(x, dataframe=TRUE) and as.data.frame(x) the values returned match the type of each layer, and can be a mix of numeric, logical, integer, and factor.

Usage

## S4 method for signature 'SpatRaster'
values(x, mat=TRUE, dataframe=FALSE, row=1, 
    nrows=nrow(x), col=1, ncols=ncol(x), na.rm=FALSE, ...)

## S4 method for signature 'SpatVector'
values(x, ...)

Arguments

x	SpatRaster or SpatVector
mat	logical. If TRUE, values are returned as a matrix instead of as a vector, except when dataframe is TRUE
dataframe	logical. If TRUE, values are returned as a data.frame instead of as a vector (also if matrix is TRUE)
row	positive integer. Row number to start from, should be between 1 and nrow(x)
nrows	positive integer. How many rows?
col	positive integer. Column number to start from, should be between 1 and ncol(x)
ncols	positive integer. How many columns? Default is the number of columns left after the start column
na.rm	logical. Remove NAs?
...	additional arguments passed to data.frame

Details

If x is a SpatRaster, and mat=FALSE, the values are returned as a vector. In cell-order by layer. If mat=TRUE, a matrix is returned in which the values of each layer are represented by a column (with ncell(x) rows). The values per layer are in cell-order, that is, from top-left, to top-right and then down by row. Use as.matrix(x, wide=TRUE) for an alternative matrix representation where the number of rows and columns matches that of x.

Value

matrix or data.frame

Note

raster values that are NA (missing) are represented by NaN (not-a-number) unless argument dataframe is TRUE.

See Also

values<-, focalValues, as.data.frame

Examples

f <- system.file("ex/elev.tif", package="terra")
r <- rast(f)
r
x <- values(r)
x[3650:3655, ]
r[3650:3655]


ff <- system.file("ex/lux.shp", package="terra")
v <- vect(ff)
y <- values(v)
head(y)

terra documentation built on Oct. 13, 2023, 5:08 p.m.