mosaic: mosaic SpatRasters

In terra: Spatial Data Analysis

mosaic SpatRasters

Description

Combine adjacent and (partly) overlapping SpatRasters to form a single new SpatRaster. Values in overlapping cells are averaged (by default) or can be computed with another function.

With the "blend" function, smooth gradients in overlappoing zones are created by weighting each raster's contribution by the distance from the cell to the raster's nearest edge.

The SpatRasters must have the same origin and spatial resolution.

If rasters do not overlap, or if their values do not need to be computed, you can use merge instead.

Usage

## S4 method for signature 'SpatRaster,SpatRaster'
mosaic(x, y, ..., fun="mean", resample=FALSE, method="",
		filename="", overwrite=FALSE, wopt=list())

## S4 method for signature 'SpatRasterCollection,missing'
mosaic(x, fun="mean", resample=FALSE, method="", filename="", ...)

Arguments

x	SpatRaster or SpatRasterCollection
y	SpatRaster if x is a SpatRaster, otherwise missing
...	additional SpatRasters
fun	character. One of "blend", "mean", "median", "min", "max", "modal", "sum", "first", "last"
resample	logical. If TRUE input rasters are resampled if they do not align (same origin and resolution) with the first raster
method	character. The resampling method used. One of "nearest", "bilinear", "cubic", "cubicspline", "lanczos", "average", "mode" as in resample. If NULL, "nearest" is used for categorical rasters and "bilinear" for other rasters
filename	character. Output filename
overwrite	logical. If TRUE, filename is overwritten
wopt	list with named options for writing files as in writeRaster

Value

SpatRaster

See Also

merge

Examples

x <- rast(xmin=-110, xmax=-60, ymin=40, ymax=70, res=1, vals=1)
y <- rast(xmin=-95, xmax=-45, ymax=60, ymin=30, res=1, vals=2)
z <- rast(xmin=-80, xmax=-30, ymax=50, ymin=20, res=1, vals=3)

m1 <- mosaic(x, y, z)

m2 <- mosaic(z, y, x)

# with a SpatRasterCollection
spc <- sprc(list(x, y, z))

m <- mosaic(spc)

b <- mosaic(spc, fun="blend")

terra documentation built on Aug. 22, 2026, 5:07 p.m.