fit.variogram.reml(formula, locations, data, model, debug.level = 1, set)
z~1
vgm
set=list(iter=100)
to set the max. number of iterations to 100.Kitanidis, P., Minimum-Variance Quadratic Estimation of Covariances of Regionalized Variables, Mathematical Geology 17 (2), 195--208, 1985