joyn (version 0.2.4)

check_dt_by: Check dt by vars

Description

check variable(s) by which data frames are joined: either a single by var, common to right and left dt, or

Usage

check_dt_by(x, y, by, by.x, by.y)

Value

character specifying checked variable(s) to join by

Arguments

x

left table

y

right table

by

character: variable to join by (common variable to x and y)

by.x

character: specified var in x to join by

by.y

character: specified var in y to join by

Examples

if (FALSE) {
x = data.table(id1 = c(1, 1, 2, 3, 3),
               id2 = c(1, 1, 2, 3, 4),
               t   = c(1L, 2L, 1L, 2L, NA_integer_),
               x   = c(16, 12, NA, NA, 15))
y = data.table(id  = c(1, 2, 5, 6, 3),
               id2 = c(1, 1, 2, 3, 4),
               y   = c(11L, 15L, 20L, 13L, 10L),
               x   = c(16:20))
# example specifying by.x and by.y
joyn:::check_dt_by(x, y, by.x = "id1", by.y = "id2")
}