update_bsplines method

[dewittpe]

Currently there are functions newknots and newdf. Replace these methods with an method update_bspline and update_btensor (made to be synonyms) method.

general idea:

update_bspline <- update_btensor <- function(object, iknots, df, bknots, order) {
  UseMethod("update_bspline")
}

update_bspline.formula <- function(object, iknots, df, bknots, order) {
  # Modify the code in the newknots and newdf calls.  See updatebspline that is currently in the predict.R file.
}

update_bspline.cpr_cp <- update_bspline.cpr_cn <- function (object, iknots, df, bknots, order) {
  update(object, formula = update_bsplines.formula(formula(object), iknots, df, bknots, order))
}

Use this method in the cpr and cnr calls. Likely will be used elsewhere.

[dewittpe]

Need to run testing and extend the documentation.

[dewittpe]

Provide examples for updating each of the types objects for which a S3 method has been provided.

• formula
• cpr_bs
• cpr_cp
• cpr_cn
• cpr_bt

It is important to note that the update_bsplines.X and update.btensor.X are synonyms for the X method.