joyn (version 0.2.4)

is_id: Check if dt is uniquely identified by by variable

Description

report if dt is uniquely identified by by var or, if report = TRUE, the duplicates in by variable

Usage

is_id(
  dt,
  by,
  verbose = getOption("joyn.verbose", default = FALSE),
  return_report = FALSE
)

Value

logical or data.frame, depending on the value of argument return_report

Arguments

dt

either right of left table

by

variable to merge by

verbose

logical: if TRUE messages will be displayed

return_report

logical: if TRUE, returns data with summary of duplicates. If FALSE, returns logical value depending on whether dt is uniquely identified by by

Examples

library(data.table)

# example with data frame not uniquely identified by `by` var

y <- data.table(id = c("c","b", "c", "a"),
                 y  = c(11L, 15L, 18L, 20L))
is_id(y, by = "id")
is_id(y, by = "id", return_report = TRUE)

# example with data frame uniquely identified by `by` var

y1 <- data.table(id = c("1","3", "2", "9"),
                 y  = c(11L, 15L, 18L, 20L))
is_id(y1, by = "id")