#Now create a confidence envelope from the original gaussian fit
 plot(parana.bin,envelope=variog.model.env(parana,
	obj.variog=parana.bin,model.pars=fit))

#Try a directional variogram to see if isotropy holds
dir.parana <- variog4(parana)
plot(dir.parana)

#Is it significant?
plot(parana.bin,envelope=variog.model.env(parana,
	obj.variog=parana.bin,model.pars=fit))
lines(dir.parana$"135",lty=4)
lines(dir.parana$"90",lty=3)
lines(dir.parana$"45",lty=2)
lines(dir.parana$"0",lty=1)


#What happens if we take out the quadratic trend first?
 dir2.parana<-variog4(parana,trend="2nd")
 plot(dir2.parana)