Count Values Using a Predicate

Counts values by rows/columns using a predicate function.

Usage

count(x, ...)

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

# S4 method for matrix
count(x, f, margin = 1, negate = FALSE, na.rm = FALSE, ...)

Arguments

x

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

...

Further arguments to be passed to f.

f

A predicate function.

margin

A length-one numeric 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?

na.rm

A logical scalar: should NA values be stripped before the computation proceeds?

Value

A numeric vector.

See also

Other data cleaning tools: compact(), detect(), discard(), empty, infinite, keep(), missing, remove_constant(), zero

Author

N. Frerebeau

Examples

## Create a 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,]    5    5    4    2   NA
#> [2,]    6    7   10    4    8
#> [3,]   NA    1    2    9    7
#> [4,]   10    2    3   NA    5
#> [5,]    3    3    7    6    9

## Count missing values in rows
count(X, f = is.na, margin = 1)
#> [1] 1 0 1 1 0
## Count non-missing values in columns
count(X, f = is.na, margin = 2, negate = TRUE)
#> V1 V2 V3 V4 V5 
#>  4  5  5  4  4