joyn (version 0.2.4)

check_y_vars_to_keep: Check variables in y that will be kept in returning table

Description

check and return variable names in y to keep in returning table, excluding those that are keys of the merge

Usage

check_y_vars_to_keep(y_vars_to_keep, y, by)

Value

character vector with variable names from y table

Arguments

y_vars_to_keep

either TRUE, if keep all vars in y; FALSE or NULL, if keep no vars; or character vector specifying which variables in y to keep

y

data frame

by

A vector of shared column names in x and y to merge on. This defaults to the shared key columns between the two tables. If y has no key columns, this defaults to the key of x.

Examples

if (FALSE) {
y1 = data.table(id = 1:2,
               y  = c(11L, 15L))
# With y_vars_to_keep TRUE
joyn:::check_y_vars_to_keep(TRUE, y1, by = "id")
# With y_vars_to_keep FALSE
joyn:::check_y_vars_to_keep(FALSE, y1, by = "id")
# Specifying which y vars to keep
joyn:::check_y_vars_to_keep("y", y1, by = "id")
}