Converts a given R object, e.g. as generated by the R Learner node as knime.model , into a corresponding PMML object that can then be used together with all KNIME predictors supporting PMML. The R object is first loaded into a new R workspace and then converted into PMML (using the PMML library in R). The toString() method in R is used to generate a character stream describing the PMML object which is written to the PMML out-port.

More details about R and PMML:
R project
PMML standard