List from the program variogram with the following components.
\$range: range of data. \$nugget: nugget effect. \$sill: sill.
\$vario: z values of the variogram. \$xh: mean distance for each class.
n
The plot covers n times the range. Default value is all the data.
fit
Also plot lines and fitted values (TRUE, the default,
or plot variogram only as points (FALSE).