Derives a new variable according to a specified function of synthesised data.
syn.passive(data, func)a data frame with synthesised data.
a formula specifying transformations on data.
It is specified as a string starting with ~.
A vector including the result of applying the formula.
Any function of the synthesised data can be specified. Note that several operators such as
+, -, * and ^ have different meanings in formula syntax. Use
the identity function I() if they should be interpreted as arithmetic operators,
e.g. "~I(age^2)".
Van Buuren, S. and Groothuis-Oudshoorn, K. (2011).
mice: Multivariate Imputation by Chained Equations
in R. Journal of Statistical Software,
45(3), 1-67.
http://www.jstatsoft.org/v45/i03/