dot-check_uniqueness function

Check the uniqueness of groups This function takes a data frame df and a vector of columns group_by, and checks whether the combinations of values in the columns specified by group_by are unique. If the combinations are not unique, a warning message is printed.

.check_uniqueness(df, group_by)

Arguments

• df: A data frame.
• group_by: A character vector of column names in df that specify the groups to check for uniqueness.

Returns

No return value, called for side effects: it will stop with an error if any group combinations are not unique.

Examples

df <- data.frame(id = c(1, 1, 1, 1, 2, 2),
                 fu = rep(c("baseline", "follow-up"), 3),
                 value = rnorm(6))
.check_uniqueness(df, c("id", "fu"))