summary.default(object, ..., digits=max(options()$digits - 3, 3))
object and
digits are ignored.
digit significant
digits.
object is numeric, the quartiles and mean of
the data, and the number of missing values if there are any.
If
object is a list, summary returns the name, length, class, and
mode of each component.
Otherwise, the length and mode are given.
The returned value is useful only for printing.
Use functions like
quantile or
mean to get numerical summaries
of data for use in other functions.
summary.default treats a matrix as one dataset, it does not summarize
each column.
summary(state.x77[,"Illiteracy"]) # Produces the following: Min. 1st Qu. Median Mean 3rd Qu. Max. 0.5 0.625 0.95 1.17 1.575 2.8