The gstat Package - NexTag Supports Open Source Initiatives

variogramLine 47variogram(log(zinc)~x+y, meuse)# directional variogram:variogram(log(zinc)~x+y, meuse, alpha=c(0,45,90,135))# GLS residual variogram:v = variogram(log(zinc)~x+y, meuse)v.fit = fit.variogram(v, vgm(1, "Sph", 700, 1))v.fitset = list(gls=1)vg = gstat(NULL, "log-zinc", log(zinc)~x+y, meuse, model=v.fit, set = set)variogram(g)if (require(rgdal)) {proj4string(meuse) = CRS("+init=epsg:28992")meuse.ll = spTransform(meuse, CRS("+proj=longlat"))# variogram of unprojected data, using great-circle distances, returning km as unitsvariogram(log(zinc) ~ 1, meuse.ll)}variogramLineSemivariance Values For a Given Variogram ModelDescriptionGenerates a semivariance values given a variogram modelUsagevariogramLine(object, maxdist, n = 200, min = 1.0e-6 * maxdist,dir = c(1,0,0), covariance = FALSE, ..., debug.level = 0)Argumentsobjectmaxdistnmindircovariance... ignoreddebug.levelvariogram model for which we want semivariance function valuesmaximum distance for which we want semivariance valuesnumber of pointsminimum distance; a value slightly larger than zero is usually used to avoid thediscontinuity at distance zero if a nugget component is presentdirection vector: unit length vector pointing the direction in x (East-West), y(North-South) and z (Up-Down)logical; if TRUE return covariance values, otherwise return semivariance valuesgstat internal debug level