raster包中的focal()函数旨在用于此类计算.以下代码返回 all 局部最大值的坐标，包括边缘上的坐标和属于高原"部分的坐标.

The focal() function in the raster package is designed for calculations like this. The following code returns coordinates of all local maxima, including those on edges and those that are parts of "plateaus ".

library(raster)

## Construct an example matrix
set.seed(444)
msize <- 10
x <- matrix(sample(seq_len(msize), msize^2, replace=TRUE), ncol=msize)

## Convert it to a raster object
r <- raster(x)
extent(r) <- extent(c(0, msize, 0, msize) + 0.5)

## Find the maximum value within the 9-cell neighborhood of each cell
f <- function(X) max(X, na.rm=TRUE)
ww <- matrix(1, nrow=3, ncol=3) ## Weight matrix for cells in moving window
localmax <- focal(r, fun=f, w=ww, pad=TRUE, padValue=NA)

## Does each cell have the maximum value in its neighborhood?
r2 <- r==localmax

## Get x-y coordinates of those cells that are local maxima
maxXY <- xyFromCell(r2, Which(r2==1, cells=TRUE))
head(maxXY)
#       x  y
# [1,]  8 10
# [2,] 10 10
# [3,]  3  9
# [4,]  4  9
# [5,]  1  8
# [6,]  6  8

# Visually inspect the data and the calculated local maxima
plot(r)   ## Plot of heights
windows() ## Open a second plotting device
plot(r2)  ## Plot showing local maxima