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Counts values by rows/columns according to a given predicate.

Usage

count(x, f, ...)

# S4 method for matrix,`function`
count(x, f, margin = 1, negate = FALSE)

# S4 method for data.frame,`function`
count(x, f, margin = 1, negate = FALSE)

Arguments

x

An object (should be a matrix or a data.frame).

f

A predicate function.

...

Currently not used.

margin

A vector giving the subscripts which the function will be applied over (1 indicates rows, 2 indicates columns).

negate

A logical scalar: should the negation of f be used instead of f?

Value

A numeric vector.

See also

Other data cleaning tools: assign(), detect(), remove(), replace()

Author

N. Frerebeau

Examples

## Create a count data matrix
X <- matrix(sample(1:10, 25, TRUE), nrow = 5, ncol = 5)

## Add NA
k <- sample(1:25, 3, FALSE)
X[k] <- NA
X
#>      [,1] [,2] [,3] [,4] [,5]
#> [1,]    7    7   NA    3    7
#> [2,]    2    4   NA    1    6
#> [3,]    5   NA    3    2   10
#> [4,]    5    8    6    9    3
#> [5,]    6    3    1    3    3

## Count missing values in rows
count(X, f = is.na, margin = 1)
#> [1] 1 1 1 0 0
## Count non-missing values in columns
count(X, f = is.na, margin = 2, negate = TRUE)
#> [1] 5 4 3 5 5

## Find row with NA
detect(X, f = is.na, margin = 1)
#> [1]  TRUE  TRUE  TRUE FALSE FALSE
## Find column without any NA
detect(X, f = is.na, margin = 2, negate = TRUE, all = TRUE)
#> [1]  TRUE FALSE FALSE  TRUE  TRUE

## Remove row with any NA
compact(X, f = is.na, margin = 1, all = FALSE)
#>      [,1] [,2] [,3] [,4] [,5]
#> [1,]    5    8    6    9    3
#> [2,]    6    3    1    3    3
## Remove column with any NA
compact(X, f = is.na, margin = 2, all = FALSE)
#>      [,1] [,2] [,3]
#> [1,]    7    3    7
#> [2,]    2    1    6
#> [3,]    5    2   10
#> [4,]    5    9    3
#> [5,]    6    3    3

## Replace NA with zeros
replace_NA(X, value = 0)
#>      [,1] [,2] [,3] [,4] [,5]
#> [1,]    7    7    0    3    7
#> [2,]    2    4    0    1    6
#> [3,]    5    0    3    2   10
#> [4,]    5    8    6    9    3
#> [5,]    6    3    1    3    3