Weighted mean of x and y coordinates (sorry for the pun :)), that is something like
n = 21 y = matrix( c(1:n), n, n) x = matrix( c(1:n), n, n, byrow = TRUE) # These are the Center of mass coordinates: xCenter = sum(x * Z)/sum(Z); yCenter = sum(y * Z)/sum(Z); If you also need the z coordinate, it simply the mean of the matrix Z. zCenter = mean(Z) Peter On Mon, Nov 8, 2010 at 9:07 AM, Ab Hu <master.rs...@yahoo.com> wrote: > > Hi all, > I have a matrix of a mountain of form 21x21 and values in them are height > (Z). Using the persp function I can view this mountain in 3D. > Now, I am trying to find a measure to find the centre of gravity (maybe > centroid?) of this mountain. Any idea what would be the best way to go? > -- > View this message in context: > http://r.789695.n4.nabble.com/Centre-of-gravity-of-a-mountain-tp3032319p3032319.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
