bestMatch: bestMatch

In terra: Spatial Data Analysis

bestMatch

Description

Determine for each grid cell which reference it is most similar to. A reference consists of a SpatVector with reference locations, or a data.frame in which each column matches a layer name in the SpatRaster.

Similarity is computed with the sum of squared differences between the cell and the reference. It may be important to first scale the input.

Usage

## S4 method for signature 'SpatRaster,SpatVector'
bestMatch(x, y, labels="", filename="", ...)

## S4 method for signature 'SpatRaster,data.frame'
bestMatch(x, y, labels="", filename="", ...)

Arguments

x	SpatRaster
y	SpatVector or data.frame
labels	character. labels that correspond to each class (row in y
filename	character. Output filename
...	additional arguments for writing files as in writeRaster

Value

SpatRaster

Examples

f <- system.file("ex/logo.tif", package = "terra")
r <- rast(f)

# locations of interest 
pts <- vect(cbind(c(25.25, 34.324, 43.003), c(54.577, 46.489, 30.905)))
pts$code <- LETTERS[1:3]

plot(r)
points(pts, pch=20, cex=2, col="red")
text(pts, "code", pos=4, halo=TRUE)

x <- scale(r)

s1 <- bestMatch(x, pts, labels=pts$code)
plot(s1)

# same result
e <- extract(x, pts, ID=FALSE)
s2 <- bestMatch(x, e, labels=c("Ap", "Nt", "Ms"))

terra documentation built on Oct. 14, 2024, 5:07 p.m.