ASReml-S reference manual - VSN International

4.4 Variance model functions 44inita vector of initial parameter values. This vector can have an optional namesattribute to set the boundary constraint for each parameter. In this case, thename of each element may be one of ”P”, ”U” or ”F” for positive, unconstrainedor fixed, respectively.modelnumber of parameters(f) form: f() fv() fh()ar1 1 2 1 + nar2 2 3 2 + nar3 3 4 3 + nsar 1 2 1 + nsar2 2 3 2 + nma1 1 2 1 + nma2 2 3 2 + narma 2 3 2 + nDetails4.4.3 Metric based models in R or R 2exp(x, init=NA, dist=NA)gau(x, init=NA, dist=NA)iexp(x, y, init=NA)igau(x, y, init=NA)ieuc(x, y, init=NA)sph(x, y, init=NA)cir(x, y, init=NA)aexp(x, y, init=NA)agau(x, y, init=NA)mtrn(x, y, phi=NA, nu=0.5, delta=1.0, alpha=0.0, lambda=2)DescriptionIncludes one dimensional exponential and gaussian power models (exp, gau), two dimensionalisotropic exponential, gaussian, euclidean, spherical and circular power models(iexp, igau, ieuc, sph, cir), anisotropic exponential and gaussian models (aexp, agau) andthe Matérn class (mtrn).Required argumentsx a field in the data frame containing the x coordinates. For one dimensional.models, coordinates are obtained as unique(x) or,if specified, from the componentnamed x in the pwrpoints argument to asreml.control().y a field in the data frame containing the y coordinates .Optional argumentsdistfor one dimensional models, a vector of coordinates; an alternative way tospecify distance information for x.