R/recast.r

In reshape: Flexibly Reshape Data

# Recast 
# \link{melt} and \link{cast} data in a single step
# 
# This conveniently wraps melting and casting a data frame into
# one step. 
#
# @arguments Data set to melt
# @arguments Casting formula, see \link{cast} for specifics
# @arguments Other arguments passed to \link{cast}
# @arguments Identifying variables. If blank, will use all non measure.var variables
# @arguments Measured variables. If blank, will use all non id.var variables
# @keyword manip
# @seealso \url{http://had.co.nz/reshape/}
#X recast(french_fries, time ~ variable, id.var=1:4)
recast <- function(data, formula, ..., id.var, measure.var) {
  
  if (any(c("id.vars", "measure.vars") %in% names(list(...)))) stop("its var, not vars\n")
  molten <- melt(data, id.var, measure.var)

  if (is.formula(formula))    formula <- deparse(formula)
  if (!is.character(formula)) formula <- as.character(formula)

  cast(molten, formula, ...)
}