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Apply functions over array margins

Source: R/apply.R
apply.Rd

Applying a function to margins of a dibble or array, including a matrix.

Usage

apply(X, MARGIN, FUN, ...)

# Default S3 method
apply(X, MARGIN, FUN, ..., simplify = TRUE)

# S3 method for class 'tbl_ddf'
apply(X, MARGIN, FUN, ...)

# S3 method for class 'ddf_col'
apply(X, MARGIN, FUN, ...)

Arguments

X

A dibble or array, including a matrix.

MARGIN

An integer or character vector giving the subscripts which the function will be applied over.

FUN

A function to be applied.

...

Optional arguments to FUN.

simplify

A logical indicating whether results should be simplified if possible.

Value

A dibble if X is a dibble. See base::apply() for the return value of the default method.

Details

apply() overrides base::apply() to make it generic. The default method calls the base version.

See also

base::apply().

Examples

x <- array(1:24, 2:4,
           list(axis1 = letters[1:2],
                axis2 = letters[1:3],
                axis3 = letters[1:4]))

apply(x, 2:3, sum)
#>      axis3
#> axis2  a  b  c  d
#>     a  3 15 27 39
#>     b  7 19 31 43
#>     c 11 23 35 47
apply(as_dibble(x), 2:3, sum)
#> # A dibble:   12
#> # Dimensions: axis2 [3], axis3 [4]
#>    axis2 axis3     .
#>    <chr> <chr> <int>
#>  1 a     a         3
#>  2 a     b        15
#>  3 a     c        27
#>  4 a     d        39
#>  5 b     a         7
#>  6 b     b        19
#>  7 b     c        31
#>  8 b     d        43
#>  9 c     a        11
#> 10 c     b        23
#> 11 c     c        35
#> 12 c     d        47

apply(x, c("axis2", "axis3"), sum)
#>      axis3
#> axis2  a  b  c  d
#>     a  3 15 27 39
#>     b  7 19 31 43
#>     c 11 23 35 47
apply(as_dibble(x), c("axis2", "axis3"), sum)
#> # A dibble:   12
#> # Dimensions: axis2 [3], axis3 [4]
#>    axis2 axis3     .
#>    <chr> <chr> <int>
#>  1 a     a         3
#>  2 a     b        15
#>  3 a     c        27
#>  4 a     d        39
#>  5 b     a         7
#>  6 b     b        19
#>  7 b     c        31
#>  8 b     d        43
#>  9 c     a        11
#> 10 c     b        23
#> 11 c     c        35
#> 12 c     d        47