update.earth {earth}R Documentation

Update an 'earth' model

Description

Update an ‘earth’ model.

Usage

## S3 method for class 'earth':
update(object = stop("no 'object' arg"),
       formula. = NULL, ..., evaluate = TRUE)

Arguments

object
formula.
... These arguments are the same as earth. The "formula." argument is treated like earth's "formula". The updated ‘call’ is printed if the trace argument is present.

evaluate If TRUE (default) evaluate the new call else return the call.

Value

The value is the same as that returned by earth. If object is the only parameter then no changes are made — the returned value will be the same as the original object.

Note

If only the following arguments are used, a forward pass is unnecessary, and update.earth will perform only the pruning pass. This is usually much faster for large models.

     trace
     pmethod
     ppenalty
     nprune
     Get.crit
     Eval.model.subsets
     Print.pruning.pass

See Also

earth

Examples

data(ozone1)
(a <- earth(O3 ~ ., data = ozone1, degree = 2))

# yields:
#    Selected 11 of 21 terms, and 8 of 9 predictors
#    Number of terms at each degree of interaction: 1 5 5
#    GCV: 13.43422     RSS: 3762.234     GRSq: 0.7913151     RSq: 0.8218252 

update(a, formula = O3 ~ . - temp) #requires forward pass and pruning

# yields:
#    Selected 15 of 21 terms, and 8 of 8 predictors
#    Number of terms at each degree of interaction: 1 5 9
#    GCV: 13.14588     RSS: 3443.265     GRSq: 0.7957941     RSq: 0.8369311 

update(a, nprune = 8)              #requires only pruning

# yields:
#    Selected 8 of 21 terms, and 6 of 9 predictors
#    Number of terms at each degree of interaction: 1 5 2
#    GCV: 15.07944     RSS: 4433.915     GRSq: 0.7657586     RSq: 0.7900152 

[Package earth version 0.1-3 Index]