library(sp)
data(meuse)
library(gstat)
v=variogram(log(zinc)~1,~x+y,meuse,cutoff=500,wi=100)
v$gamma=c(0.5,1,2,3,3)
fit.variogram(v, vgm(1, "Sph", 300, 0),warn.if.neg=TRUE)
fit.variogram(v, vgm(1, "Sph", 300, 0),warn.if.neg=FALSE)