R: Missing Value, Zero-length Vector, or Zero Value of the...

RelevantNA {spatstat.utils} | R Documentation

## Missing Value, Zero-length Vector, or Zero Value of the Appropriate Type

### Description

Given any data `x`, these functions return the missing value `NA`, the empty vector, or the equivalent of the number `0`, with the same type as `x`.

### Usage

    RelevantZero(x)
    RelevantNA(x)
    RelevantEmpty(x)

    isRelevantZero(x)

### Arguments

`x` | Data of any type.

### Details

In the R system, missing values may have different types. For example, if an entry is missing from a numeric vector, it is a missing numeric value, not a missing logical value, and R distinguishes between these two types of missing values.

The function `RelevantNA` returns a missing value of the same type as the input `x` (as defined by `typeof`). Thus, `RelevantNA(3.2)` returns a missing numeric value and `RelevantNA(TRUE)` returns a missing logical value.

`RelevantEmpty(x)` returns a vector of length zero which has the same type as `x`. Thus, `RelevantEmpty(TRUE)` is equivalent to `logical(0)`.

`RelevantZero(x)` returns a single value, of the same type as `x`, that is equivalent to the number zero. For example, `RelevantZero(TRUE)` returns `FALSE`.

The function `isRelevantZero` tests whether `x` is a single zero value, by testing whether `x` is identical to `RelevantZero(x)`.

### Value

`RelevantZero` and `RelevantNA` return a single value of the same type as `x`.

`RelevantEmpty` returns a zero-length vector of the same type as `x`.

`isRelevantZero` returns a single logical value.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au.

### See Also

`typeof`

### Examples

       RelevantZero(42)
       RelevantZero(TRUE)
       RelevantZero("hello world")

       RelevantNA(1:3)
       typeof(RelevantNA(1:3))
       typeof(RelevantNA("hello world"))

[Package spatstat.utils version 2.3-1 Index]