detect {arkhe}

Find Rows/Columns Using a Predicate

Description

Finds rows/columns in an array-like object using a predicate function.

Usage

detect(x, ...)

## S4 method for signature 'ANY'
detect(x, f, margin = 1, negate = FALSE, all = 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?

all

A logical scalar. If TRUE, only the rows/columns whose values all meet the condition defined by f are considered. If FALSE (the default), only rows/columns where at least one value validates the condition defined by f are considered.

na.rm

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

Value

A logical vector.

Author(s)

N. Frerebeau

See Also

Other data preparation tools: append(), assign(), compact(), count(), discard(), get(), keep(), seek()

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

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