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[Stable]

Usage

n_(...)

N_(...)

Arguments

...

<tidy-select>

Columns to pick.

You can't pick grouping columns because they are already automatically handled by the verb (i.e. summarise() or mutate()).

Value

A numeric vector representing the count from n to N.

Details

These functions are used for indexing observations or generating sequences of numbers.

  • n_() generates a running counter within a group of variables and represents the number of the current observation.

  • N_() provides the total count within each group of variables.

You can do these operations using dplyr::n() in this way. See examples below using iris dataset.

iris |> mutate(.N_ = n()) |> head() iris |> mutate(.n_ = 1:n()) |> head() iris |> group_by(Species) |> mutate(.n_ = 1:n()) |> slice(1:5) |> ungroup()

See also

Other Data Management: append(), codebook(), cut(), tag_duplicates()

Examples


# Example with a custom dataset
df <- data.frame(
  x = c(1, 1, 2, 2, 2, 3, 4, 4, 4, 4),
  y = letters[1:10]
)

library(dplyr)
#> 
#> Attaching package: ‘dplyr’
#> The following objects are masked from ‘package:stats’:
#> 
#>     filter, lag
#> The following objects are masked from ‘package:base’:
#> 
#>     intersect, setdiff, setequal, union

# Generate a running counter for each observation within the "x" group using mutate()
mutate(df, n = n_(x))
#>    x y n
#> 1  1 a 1
#> 2  1 b 2
#> 3  2 c 1
#> 4  2 d 2
#> 5  2 e 3
#> 6  3 f 1
#> 7  4 g 1
#> 8  4 h 2
#> 9  4 i 3
#> 10 4 j 4

# Generate a running counter for each observation for all columns using mutate()
mutate(df, n = n_(everything()))
#>    x y n
#> 1  1 a 1
#> 2  1 b 1
#> 3  2 c 1
#> 4  2 d 1
#> 5  2 e 1
#> 6  3 f 1
#> 7  4 g 1
#> 8  4 h 1
#> 9  4 i 1
#> 10 4 j 1

# Generate the total count of observations using summarise()
reframe(df, n = n_(x))
#>    n
#> 1  1
#> 2  2
#> 3  1
#> 4  2
#> 5  3
#> 6  1
#> 7  1
#> 8  2
#> 9  3
#> 10 4

# Generate the total count of observations within the "x" group using summarise()
mutate(df, N = N_(everything()))
#>    x y N
#> 1  1 a 1
#> 2  1 b 1
#> 3  2 c 1
#> 4  2 d 1
#> 5  2 e 1
#> 6  3 f 1
#> 7  4 g 1
#> 8  4 h 1
#> 9  4 i 1
#> 10 4 j 1
mutate(df, N = N_(x))
#>    x y N
#> 1  1 a 2
#> 2  1 b 2
#> 3  2 c 3
#> 4  2 d 3
#> 5  2 e 3
#> 6  3 f 1
#> 7  4 g 4
#> 8  4 h 4
#> 9  4 i 4
#> 10 4 j 4
reframe(df, N = N_(x))
#>    N
#> 1  2
#> 2  2
#> 3  3
#> 4  3
#> 5  3
#> 6  1
#> 7  4
#> 8  4
#> 9  4
#> 10 4

# iris dataset
mutate(iris, n = n_(everything()))
#>     Sepal.Length Sepal.Width Petal.Length Petal.Width    Species n
#> 1            5.1         3.5          1.4         0.2     setosa 1
#> 2            4.9         3.0          1.4         0.2     setosa 1
#> 3            4.7         3.2          1.3         0.2     setosa 1
#> 4            4.6         3.1          1.5         0.2     setosa 1
#> 5            5.0         3.6          1.4         0.2     setosa 1
#> 6            5.4         3.9          1.7         0.4     setosa 1
#> 7            4.6         3.4          1.4         0.3     setosa 1
#> 8            5.0         3.4          1.5         0.2     setosa 1
#> 9            4.4         2.9          1.4         0.2     setosa 1
#> 10           4.9         3.1          1.5         0.1     setosa 1
#> 11           5.4         3.7          1.5         0.2     setosa 1
#> 12           4.8         3.4          1.6         0.2     setosa 1
#> 13           4.8         3.0          1.4         0.1     setosa 1
#> 14           4.3         3.0          1.1         0.1     setosa 1
#> 15           5.8         4.0          1.2         0.2     setosa 1
#> 16           5.7         4.4          1.5         0.4     setosa 1
#> 17           5.4         3.9          1.3         0.4     setosa 1
#> 18           5.1         3.5          1.4         0.3     setosa 1
#> 19           5.7         3.8          1.7         0.3     setosa 1
#> 20           5.1         3.8          1.5         0.3     setosa 1
#> 21           5.4         3.4          1.7         0.2     setosa 1
#> 22           5.1         3.7          1.5         0.4     setosa 1
#> 23           4.6         3.6          1.0         0.2     setosa 1
#> 24           5.1         3.3          1.7         0.5     setosa 1
#> 25           4.8         3.4          1.9         0.2     setosa 1
#> 26           5.0         3.0          1.6         0.2     setosa 1
#> 27           5.0         3.4          1.6         0.4     setosa 1
#> 28           5.2         3.5          1.5         0.2     setosa 1
#> 29           5.2         3.4          1.4         0.2     setosa 1
#> 30           4.7         3.2          1.6         0.2     setosa 1
#> 31           4.8         3.1          1.6         0.2     setosa 1
#> 32           5.4         3.4          1.5         0.4     setosa 1
#> 33           5.2         4.1          1.5         0.1     setosa 1
#> 34           5.5         4.2          1.4         0.2     setosa 1
#> 35           4.9         3.1          1.5         0.2     setosa 1
#> 36           5.0         3.2          1.2         0.2     setosa 1
#> 37           5.5         3.5          1.3         0.2     setosa 1
#> 38           4.9         3.6          1.4         0.1     setosa 1
#> 39           4.4         3.0          1.3         0.2     setosa 1
#> 40           5.1         3.4          1.5         0.2     setosa 1
#> 41           5.0         3.5          1.3         0.3     setosa 1
#> 42           4.5         2.3          1.3         0.3     setosa 1
#> 43           4.4         3.2          1.3         0.2     setosa 1
#> 44           5.0         3.5          1.6         0.6     setosa 1
#> 45           5.1         3.8          1.9         0.4     setosa 1
#> 46           4.8         3.0          1.4         0.3     setosa 1
#> 47           5.1         3.8          1.6         0.2     setosa 1
#> 48           4.6         3.2          1.4         0.2     setosa 1
#> 49           5.3         3.7          1.5         0.2     setosa 1
#> 50           5.0         3.3          1.4         0.2     setosa 1
#> 51           7.0         3.2          4.7         1.4 versicolor 1
#> 52           6.4         3.2          4.5         1.5 versicolor 1
#> 53           6.9         3.1          4.9         1.5 versicolor 1
#> 54           5.5         2.3          4.0         1.3 versicolor 1
#> 55           6.5         2.8          4.6         1.5 versicolor 1
#> 56           5.7         2.8          4.5         1.3 versicolor 1
#> 57           6.3         3.3          4.7         1.6 versicolor 1
#> 58           4.9         2.4          3.3         1.0 versicolor 1
#> 59           6.6         2.9          4.6         1.3 versicolor 1
#> 60           5.2         2.7          3.9         1.4 versicolor 1
#> 61           5.0         2.0          3.5         1.0 versicolor 1
#> 62           5.9         3.0          4.2         1.5 versicolor 1
#> 63           6.0         2.2          4.0         1.0 versicolor 1
#> 64           6.1         2.9          4.7         1.4 versicolor 1
#> 65           5.6         2.9          3.6         1.3 versicolor 1
#> 66           6.7         3.1          4.4         1.4 versicolor 1
#> 67           5.6         3.0          4.5         1.5 versicolor 1
#> 68           5.8         2.7          4.1         1.0 versicolor 1
#> 69           6.2         2.2          4.5         1.5 versicolor 1
#> 70           5.6         2.5          3.9         1.1 versicolor 1
#> 71           5.9         3.2          4.8         1.8 versicolor 1
#> 72           6.1         2.8          4.0         1.3 versicolor 1
#> 73           6.3         2.5          4.9         1.5 versicolor 1
#> 74           6.1         2.8          4.7         1.2 versicolor 1
#> 75           6.4         2.9          4.3         1.3 versicolor 1
#> 76           6.6         3.0          4.4         1.4 versicolor 1
#> 77           6.8         2.8          4.8         1.4 versicolor 1
#> 78           6.7         3.0          5.0         1.7 versicolor 1
#> 79           6.0         2.9          4.5         1.5 versicolor 1
#> 80           5.7         2.6          3.5         1.0 versicolor 1
#> 81           5.5         2.4          3.8         1.1 versicolor 1
#> 82           5.5         2.4          3.7         1.0 versicolor 1
#> 83           5.8         2.7          3.9         1.2 versicolor 1
#> 84           6.0         2.7          5.1         1.6 versicolor 1
#> 85           5.4         3.0          4.5         1.5 versicolor 1
#> 86           6.0         3.4          4.5         1.6 versicolor 1
#> 87           6.7         3.1          4.7         1.5 versicolor 1
#> 88           6.3         2.3          4.4         1.3 versicolor 1
#> 89           5.6         3.0          4.1         1.3 versicolor 1
#> 90           5.5         2.5          4.0         1.3 versicolor 1
#> 91           5.5         2.6          4.4         1.2 versicolor 1
#> 92           6.1         3.0          4.6         1.4 versicolor 1
#> 93           5.8         2.6          4.0         1.2 versicolor 1
#> 94           5.0         2.3          3.3         1.0 versicolor 1
#> 95           5.6         2.7          4.2         1.3 versicolor 1
#> 96           5.7         3.0          4.2         1.2 versicolor 1
#> 97           5.7         2.9          4.2         1.3 versicolor 1
#> 98           6.2         2.9          4.3         1.3 versicolor 1
#> 99           5.1         2.5          3.0         1.1 versicolor 1
#> 100          5.7         2.8          4.1         1.3 versicolor 1
#> 101          6.3         3.3          6.0         2.5  virginica 1
#> 102          5.8         2.7          5.1         1.9  virginica 1
#> 103          7.1         3.0          5.9         2.1  virginica 1
#> 104          6.3         2.9          5.6         1.8  virginica 1
#> 105          6.5         3.0          5.8         2.2  virginica 1
#> 106          7.6         3.0          6.6         2.1  virginica 1
#> 107          4.9         2.5          4.5         1.7  virginica 1
#> 108          7.3         2.9          6.3         1.8  virginica 1
#> 109          6.7         2.5          5.8         1.8  virginica 1
#> 110          7.2         3.6          6.1         2.5  virginica 1
#> 111          6.5         3.2          5.1         2.0  virginica 1
#> 112          6.4         2.7          5.3         1.9  virginica 1
#> 113          6.8         3.0          5.5         2.1  virginica 1
#> 114          5.7         2.5          5.0         2.0  virginica 1
#> 115          5.8         2.8          5.1         2.4  virginica 1
#> 116          6.4         3.2          5.3         2.3  virginica 1
#> 117          6.5         3.0          5.5         1.8  virginica 1
#> 118          7.7         3.8          6.7         2.2  virginica 1
#> 119          7.7         2.6          6.9         2.3  virginica 1
#> 120          6.0         2.2          5.0         1.5  virginica 1
#> 121          6.9         3.2          5.7         2.3  virginica 1
#> 122          5.6         2.8          4.9         2.0  virginica 1
#> 123          7.7         2.8          6.7         2.0  virginica 1
#> 124          6.3         2.7          4.9         1.8  virginica 1
#> 125          6.7         3.3          5.7         2.1  virginica 1
#> 126          7.2         3.2          6.0         1.8  virginica 1
#> 127          6.2         2.8          4.8         1.8  virginica 1
#> 128          6.1         3.0          4.9         1.8  virginica 1
#> 129          6.4         2.8          5.6         2.1  virginica 1
#> 130          7.2         3.0          5.8         1.6  virginica 1
#> 131          7.4         2.8          6.1         1.9  virginica 1
#> 132          7.9         3.8          6.4         2.0  virginica 1
#> 133          6.4         2.8          5.6         2.2  virginica 1
#> 134          6.3         2.8          5.1         1.5  virginica 1
#> 135          6.1         2.6          5.6         1.4  virginica 1
#> 136          7.7         3.0          6.1         2.3  virginica 1
#> 137          6.3         3.4          5.6         2.4  virginica 1
#> 138          6.4         3.1          5.5         1.8  virginica 1
#> 139          6.0         3.0          4.8         1.8  virginica 1
#> 140          6.9         3.1          5.4         2.1  virginica 1
#> 141          6.7         3.1          5.6         2.4  virginica 1
#> 142          6.9         3.1          5.1         2.3  virginica 1
#> 143          5.8         2.7          5.1         1.9  virginica 2
#> 144          6.8         3.2          5.9         2.3  virginica 1
#> 145          6.7         3.3          5.7         2.5  virginica 1
#> 146          6.7         3.0          5.2         2.3  virginica 1
#> 147          6.3         2.5          5.0         1.9  virginica 1
#> 148          6.5         3.0          5.2         2.0  virginica 1
#> 149          6.2         3.4          5.4         2.3  virginica 1
#> 150          5.9         3.0          5.1         1.8  virginica 1
mutate(iris, N = N_(everything()))
#>     Sepal.Length Sepal.Width Petal.Length Petal.Width    Species N
#> 1            5.1         3.5          1.4         0.2     setosa 1
#> 2            4.9         3.0          1.4         0.2     setosa 1
#> 3            4.7         3.2          1.3         0.2     setosa 1
#> 4            4.6         3.1          1.5         0.2     setosa 1
#> 5            5.0         3.6          1.4         0.2     setosa 1
#> 6            5.4         3.9          1.7         0.4     setosa 1
#> 7            4.6         3.4          1.4         0.3     setosa 1
#> 8            5.0         3.4          1.5         0.2     setosa 1
#> 9            4.4         2.9          1.4         0.2     setosa 1
#> 10           4.9         3.1          1.5         0.1     setosa 1
#> 11           5.4         3.7          1.5         0.2     setosa 1
#> 12           4.8         3.4          1.6         0.2     setosa 1
#> 13           4.8         3.0          1.4         0.1     setosa 1
#> 14           4.3         3.0          1.1         0.1     setosa 1
#> 15           5.8         4.0          1.2         0.2     setosa 1
#> 16           5.7         4.4          1.5         0.4     setosa 1
#> 17           5.4         3.9          1.3         0.4     setosa 1
#> 18           5.1         3.5          1.4         0.3     setosa 1
#> 19           5.7         3.8          1.7         0.3     setosa 1
#> 20           5.1         3.8          1.5         0.3     setosa 1
#> 21           5.4         3.4          1.7         0.2     setosa 1
#> 22           5.1         3.7          1.5         0.4     setosa 1
#> 23           4.6         3.6          1.0         0.2     setosa 1
#> 24           5.1         3.3          1.7         0.5     setosa 1
#> 25           4.8         3.4          1.9         0.2     setosa 1
#> 26           5.0         3.0          1.6         0.2     setosa 1
#> 27           5.0         3.4          1.6         0.4     setosa 1
#> 28           5.2         3.5          1.5         0.2     setosa 1
#> 29           5.2         3.4          1.4         0.2     setosa 1
#> 30           4.7         3.2          1.6         0.2     setosa 1
#> 31           4.8         3.1          1.6         0.2     setosa 1
#> 32           5.4         3.4          1.5         0.4     setosa 1
#> 33           5.2         4.1          1.5         0.1     setosa 1
#> 34           5.5         4.2          1.4         0.2     setosa 1
#> 35           4.9         3.1          1.5         0.2     setosa 1
#> 36           5.0         3.2          1.2         0.2     setosa 1
#> 37           5.5         3.5          1.3         0.2     setosa 1
#> 38           4.9         3.6          1.4         0.1     setosa 1
#> 39           4.4         3.0          1.3         0.2     setosa 1
#> 40           5.1         3.4          1.5         0.2     setosa 1
#> 41           5.0         3.5          1.3         0.3     setosa 1
#> 42           4.5         2.3          1.3         0.3     setosa 1
#> 43           4.4         3.2          1.3         0.2     setosa 1
#> 44           5.0         3.5          1.6         0.6     setosa 1
#> 45           5.1         3.8          1.9         0.4     setosa 1
#> 46           4.8         3.0          1.4         0.3     setosa 1
#> 47           5.1         3.8          1.6         0.2     setosa 1
#> 48           4.6         3.2          1.4         0.2     setosa 1
#> 49           5.3         3.7          1.5         0.2     setosa 1
#> 50           5.0         3.3          1.4         0.2     setosa 1
#> 51           7.0         3.2          4.7         1.4 versicolor 1
#> 52           6.4         3.2          4.5         1.5 versicolor 1
#> 53           6.9         3.1          4.9         1.5 versicolor 1
#> 54           5.5         2.3          4.0         1.3 versicolor 1
#> 55           6.5         2.8          4.6         1.5 versicolor 1
#> 56           5.7         2.8          4.5         1.3 versicolor 1
#> 57           6.3         3.3          4.7         1.6 versicolor 1
#> 58           4.9         2.4          3.3         1.0 versicolor 1
#> 59           6.6         2.9          4.6         1.3 versicolor 1
#> 60           5.2         2.7          3.9         1.4 versicolor 1
#> 61           5.0         2.0          3.5         1.0 versicolor 1
#> 62           5.9         3.0          4.2         1.5 versicolor 1
#> 63           6.0         2.2          4.0         1.0 versicolor 1
#> 64           6.1         2.9          4.7         1.4 versicolor 1
#> 65           5.6         2.9          3.6         1.3 versicolor 1
#> 66           6.7         3.1          4.4         1.4 versicolor 1
#> 67           5.6         3.0          4.5         1.5 versicolor 1
#> 68           5.8         2.7          4.1         1.0 versicolor 1
#> 69           6.2         2.2          4.5         1.5 versicolor 1
#> 70           5.6         2.5          3.9         1.1 versicolor 1
#> 71           5.9         3.2          4.8         1.8 versicolor 1
#> 72           6.1         2.8          4.0         1.3 versicolor 1
#> 73           6.3         2.5          4.9         1.5 versicolor 1
#> 74           6.1         2.8          4.7         1.2 versicolor 1
#> 75           6.4         2.9          4.3         1.3 versicolor 1
#> 76           6.6         3.0          4.4         1.4 versicolor 1
#> 77           6.8         2.8          4.8         1.4 versicolor 1
#> 78           6.7         3.0          5.0         1.7 versicolor 1
#> 79           6.0         2.9          4.5         1.5 versicolor 1
#> 80           5.7         2.6          3.5         1.0 versicolor 1
#> 81           5.5         2.4          3.8         1.1 versicolor 1
#> 82           5.5         2.4          3.7         1.0 versicolor 1
#> 83           5.8         2.7          3.9         1.2 versicolor 1
#> 84           6.0         2.7          5.1         1.6 versicolor 1
#> 85           5.4         3.0          4.5         1.5 versicolor 1
#> 86           6.0         3.4          4.5         1.6 versicolor 1
#> 87           6.7         3.1          4.7         1.5 versicolor 1
#> 88           6.3         2.3          4.4         1.3 versicolor 1
#> 89           5.6         3.0          4.1         1.3 versicolor 1
#> 90           5.5         2.5          4.0         1.3 versicolor 1
#> 91           5.5         2.6          4.4         1.2 versicolor 1
#> 92           6.1         3.0          4.6         1.4 versicolor 1
#> 93           5.8         2.6          4.0         1.2 versicolor 1
#> 94           5.0         2.3          3.3         1.0 versicolor 1
#> 95           5.6         2.7          4.2         1.3 versicolor 1
#> 96           5.7         3.0          4.2         1.2 versicolor 1
#> 97           5.7         2.9          4.2         1.3 versicolor 1
#> 98           6.2         2.9          4.3         1.3 versicolor 1
#> 99           5.1         2.5          3.0         1.1 versicolor 1
#> 100          5.7         2.8          4.1         1.3 versicolor 1
#> 101          6.3         3.3          6.0         2.5  virginica 1
#> 102          5.8         2.7          5.1         1.9  virginica 2
#> 103          7.1         3.0          5.9         2.1  virginica 1
#> 104          6.3         2.9          5.6         1.8  virginica 1
#> 105          6.5         3.0          5.8         2.2  virginica 1
#> 106          7.6         3.0          6.6         2.1  virginica 1
#> 107          4.9         2.5          4.5         1.7  virginica 1
#> 108          7.3         2.9          6.3         1.8  virginica 1
#> 109          6.7         2.5          5.8         1.8  virginica 1
#> 110          7.2         3.6          6.1         2.5  virginica 1
#> 111          6.5         3.2          5.1         2.0  virginica 1
#> 112          6.4         2.7          5.3         1.9  virginica 1
#> 113          6.8         3.0          5.5         2.1  virginica 1
#> 114          5.7         2.5          5.0         2.0  virginica 1
#> 115          5.8         2.8          5.1         2.4  virginica 1
#> 116          6.4         3.2          5.3         2.3  virginica 1
#> 117          6.5         3.0          5.5         1.8  virginica 1
#> 118          7.7         3.8          6.7         2.2  virginica 1
#> 119          7.7         2.6          6.9         2.3  virginica 1
#> 120          6.0         2.2          5.0         1.5  virginica 1
#> 121          6.9         3.2          5.7         2.3  virginica 1
#> 122          5.6         2.8          4.9         2.0  virginica 1
#> 123          7.7         2.8          6.7         2.0  virginica 1
#> 124          6.3         2.7          4.9         1.8  virginica 1
#> 125          6.7         3.3          5.7         2.1  virginica 1
#> 126          7.2         3.2          6.0         1.8  virginica 1
#> 127          6.2         2.8          4.8         1.8  virginica 1
#> 128          6.1         3.0          4.9         1.8  virginica 1
#> 129          6.4         2.8          5.6         2.1  virginica 1
#> 130          7.2         3.0          5.8         1.6  virginica 1
#> 131          7.4         2.8          6.1         1.9  virginica 1
#> 132          7.9         3.8          6.4         2.0  virginica 1
#> 133          6.4         2.8          5.6         2.2  virginica 1
#> 134          6.3         2.8          5.1         1.5  virginica 1
#> 135          6.1         2.6          5.6         1.4  virginica 1
#> 136          7.7         3.0          6.1         2.3  virginica 1
#> 137          6.3         3.4          5.6         2.4  virginica 1
#> 138          6.4         3.1          5.5         1.8  virginica 1
#> 139          6.0         3.0          4.8         1.8  virginica 1
#> 140          6.9         3.1          5.4         2.1  virginica 1
#> 141          6.7         3.1          5.6         2.4  virginica 1
#> 142          6.9         3.1          5.1         2.3  virginica 1
#> 143          5.8         2.7          5.1         1.9  virginica 2
#> 144          6.8         3.2          5.9         2.3  virginica 1
#> 145          6.7         3.3          5.7         2.5  virginica 1
#> 146          6.7         3.0          5.2         2.3  virginica 1
#> 147          6.3         2.5          5.0         1.9  virginica 1
#> 148          6.5         3.0          5.2         2.0  virginica 1
#> 149          6.2         3.4          5.4         2.3  virginica 1
#> 150          5.9         3.0          5.1         1.8  virginica 1