pairwise distance matrix of cell centroids in a raster grid in R

Asked Nov 15 '14 at 20:22

Active Nov 15 '14 at 20:22

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I want to get a pairwise distance matrix between the centroids of every cell with every other cell in a raster layer. As well, I'm trying to figure out how to get the pairwise matrix of differences between values within the raster layer.

I tried looking at the {gdistance} and {spatstat} packages but it doesn't seem like there is a function for this.

Here is an example:

df <- data.frame(x = rnorm(100, 5, 3), y = rnorm(100, 10, 6))

rast <- raster()
ncol <- 20
nrow <- 20
test <- rasterize(df, rast, FUN=mean)
plot(test, xlim=c(min(df$x), max(df$x)), ylim=c(min(df$y), max(df$x)))

Any ideas?

asked Nov 15 '14 at 20:22

user3389288

something like [xyFromCell](http://www.inside-r.org/packages/cran/raster/docs/xyFromCell)? – Paulo E. Cardoso Nov 16 '14 at 15:01
you'll probably need a 16Gb RAM machine to deal with this. – Paulo E. Cardoso Nov 16 '14 at 15:13
I could try to convert the raster data to point data, then take the pairwise distance matrix of the points. – user3389288 Nov 16 '14 at 17:18
You'll need a different approach, other than simple `dist` maybe with a function to apply dist by row or use other memory efficient approach. – Paulo E. Cardoso Nov 16 '14 at 17:27
I was thinking something similar to [this](http://stackoverflow.com/questions/22947448/finding-euclidean-distance-in-rspatstat-between-points-confined-by-an-irregul) – user3389288 Nov 16 '14 at 17:35
You want the distance to each of the 10,000 points from each of the 10,000 points? How do you intend to store that? As 10,000 rasters? – jbaums Nov 26 '14 at 16:41

pairwise distance matrix of cell centroids in a raster grid in R

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