earth (version 2.3-0)

mars.to.earth: Convert a "mars" object to an "earth" object

Description

Convert a mars object to an earth object

Usage

mars.to.earth(object)

Arguments

object

A "mars" object, created using mars in the mda package.

Value

• The value is the same format as that returned by earth but with skeletal versions of rss.per.subset, gcv.per.subset, and prune.terms. You can fully initialize these components by calling update.earth after mars.to.earth, but if you do this selected.terms may change. However with pmethod="backward" a change is unlikely --- selected.terms would change only if GCVs are so close that numerical errors have an effect.

See Also

earth, mars

Examples

if (require(mda)) {
    a <- mars(trees[,-3], trees[,3])
    a <- mars.to.earth(a)
    summary(a, digits = 2) # the standard earth functions can now be used

    # yields (note the reconstructed call):
    #    Call: earth(x=trees[, -3], y=trees[, 3])
    #
    #                    y
    #   (Intercept)  19.76
    #   h(Girth-12)   5.40
    #   h(12-Girth)  -2.56
    #   h(Height-76)  0.72
    #
    #   Selected 4 of 5 terms, and 2 of 2 predictors
    #   Importance: Girth, Height
    #   Number of terms at each degree of interaction: 1 3 (additive model)
    #   GCV 13    RSS 251    GRSq 0.95    RSq 0.97
}