Stamp is like reshape but the "stamping" function is passed the entire data frame, instead of just a few variables.
stamp(data, formula = . ~ ., fun.aggregate, ..., margins=NULL,
subset=TRUE, add.missing=FALSE)data.frame (no molten)
formula that describes arrangement of result, columns ~ rows, see reshape for more information
aggregation function to use, should take a data frame as the first argument
arguments passed to the aggregation function
margins to compute (character vector, or TRUE for all margins), can contain grand_row or grand_col to inclue grand row or column margins respectively.
logical vector by which to subset the data frame, evaluated in the context of the data frame so you can
fill in missing combinations?
It is very similar to the by function except in the form
of the output which is arranged using the formula as in reshape
Note that it's very easy to create objects that R can't print with this function. You will probably want to save the results to a variable and then use extract the results. See the examples.