focalReg function

Focal regression

Calculate values for a moving-window by comparing the value in one layers with the values in one to many other layers. A typical case is the computation of the coefficients for a focal linear regression model.

## S4 method for signature 'SpatRaster'
focalReg(x, w=3, fun="ols", ..., fillvalue=NA, filename="", overwrite=FALSE, wopt=list())

Arguments

• x: SpatRaster with at least two layers. The first is the "Y" (dependent) variable and the remainder are the "X" (independent) variables
• w: numeric or matrix to define the focal window. The window an be defined as one (for a square) or two numbers (row, col); or with an odd-sized weights matrix. See the Details section in focal. Note that if a matrix with numbers other than zero or one are used, the values are used as weights. For this to work, fun must have an argument weights
• fun: a function with at least two arguments (one for each layer). There is a built-in function "ols" for both the weighted and unweighted Ordinary Least Square regression. This function has an additional argument na.rm=FALSE and intercept=TRUE
• ...: additional arguments for fun
• fillvalue: numeric. The value of the cells in the virtual rows and columns outside of the raster
• filename: character. Output filename
• overwrite: logical. If TRUE, filename is overwritten
• wopt: additional arguments for writing files as in writeRaster

Returns

SpatRaster

See Also

focal, focal3D, focalValues

Examples

r <- rast(ncols=10, nrows=10, ext(0, 10, 0, 10))
values(r) <- 1:ncell(r)
x <- c(r, init(r, runif) * r)
f <- focalReg(x, 3)