> From: "sibonile sibanda" <[EMAIL PROTECTED]> > Subject: [R-sig-Geo] Moving Average/Surface > > Is there a way to do moving average interpolation or moving surface in R > from point data?
In the `spatstat' package the function density.ppp has an argument `weights'. This can be used to perform spatial interpolation of values recorded at arbitrary point locations, using kernel smoothing. Suppose X is the point pattern of locations (an object of class "ppp") and Y is the corresponding vector of values to be interpolated. Then num <- density(X, weights=Y) den <- density(X) Z <- eval.im(num/den) calculates the standard kernel-weighted average. The argument `sigma' of density.ppp can be used to control the smoothing bandwidth. The result Z is a pixel image (object of class "im") that can be plotted using plot.im, contour.im, image.im, persp.im etc. For other kinds of smoothing, look at package `akima' Adrian Baddeley _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo