summary.ClarkLDF and summary.ClarkCapeCod return
data.frames whose columns are objects of the appropriate mode
(i.e., character for "Origin", otherwise numeric)
Details
summary.ClarkLDF returns a data.frame that holds the columns of a
typical "Development-type" exhibit.
summary.ClarkCapeCod returns a data.frame that holds the columns of a
typical "Bornhuetter-Ferguson-type" exhibit.