| count_dupes | R Documentation | 
count_dupes() returns values of by variables for which the .data has
multiple rows, along with the number of rows for each combination of values.
assert_unique() throws an error if there are multiple rows for any
combination of by variable values
count_dupes(.data, by, setkey = FALSE)
assert_unique(.data, by, data_chr, by_chr)
| .data | A data frame or data table | 
| by | tidy-select. Columns in  | 
| setkey | Logical. Should the output be keyed by  | 
| data_chr | optional. character. You can use this argument to manually specify
the name of  | 
| by_chr | optional. character. You can use this argument to manually specify
the name of  | 
count_dupes()A data.table with the (filtered) by
columns and an additional column "n_rows" which shows the number of rows in
.data having the combination of by values shown in the output
row.
assert_unique()No return value. Called to throw an error depending on the input.
df <- read.table(text = "
x y z
1 6 1
2 6 2
3 7 3
3 7 4
4 3 5
4 3 6
", header = TRUE)
count_dupes(df, c(x, y))
## Not run: 
assert_unique(df, c(x, y))
## End(Not run)
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