getCommonChunk: Save the common columns for each tsv to one chunk
Description
Save the common columns for each tsv to one chunk
Usage
getCommonChunk(built, chunk.vars, aes.list)
Arguments
built
data.frame of built data.
aes.list
a character vector of aesthetics.
vars
character vector of chunk variable names to split on.
Value
a list of common and varied data to save, or NULL if there is
no common data.