Returns subsets of a
# S3 method for data.table subset(x, subset, select, ...)
data.table to subset.
logical expression indicating elements or rows to keep
expression indicating columns to select from
further arguments to be passed to or from other methods
subset argument works on the rows and will be evaluated
data.table so columns can be referred to (by name) as variables
in the expression.
data.table that is returned will maintain the original keys
as long as they are not
data.table containing the subset of rows and columns that are