isReplicated {R.utils} R Documentation

## Identifies all entries with replicated values

### Description

Identifies all entries with replicated values, that is, with values that exist more than once.

### Usage

``` isReplicated(x, ...)
replicates(x, ...)
```

### Arguments

 `x` A `vector` of length K. `...` Additional arguments passed to `duplicated`().

### Details

Let `reps <- isReplicated(x)`. Then it always holds that:

• `reps == rev(isReplicated(rev(x)))`

• `reps == duplicated(x) | duplicated(x, fromLast=TRUE)`

• `reps == !is.element(x, setdiff(x, unique(x[duplicated(x)])))`

### Value

A `logical` `vector` of length K, where `TRUE` indicates that the value exists elsewhere, otherwise not.

### Author(s)

Henrik Bengtsson

Internally `duplicated`() is used. See also `isSingle`().

### Examples

```
x <- c(1,1,2,3,4,2,1)
x <- base::letters[x]
print(x)

# Identify entries with replicated values
reps <- isReplicated(x)
print(x[reps])
stopifnot(x[reps] == replicates(x))

# Identify entries with unique values
print(x[!reps])
stopifnot(x[!reps] == singles(x))

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Validation
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
x <- c(1,1,2,3,4,2,1)
x <- base::letters[x]
reps <- isReplicated(x)

stopifnot(all(table(x[reps]) > 1))
stopifnot(all(table(x[!reps]) == 1))
stopifnot(all(reps == rev(isReplicated(rev(x)))))
stopifnot(all(reps == duplicated(x) | duplicated(x, fromLast=TRUE)))
stopifnot(all(reps == !is.element(x, setdiff(x, unique(x[duplicated(x)])))))
stopifnot(all(sort(c(singles(x), replicates(x))) == sort(x)))

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Benchmarking singles()
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
set.seed(0xBEEF)
n <- 1e6
x <- sample(1:(n/2), size=n, replace=TRUE)
t <- system.time({
s <- isSingle(x)
})
print(sum(s))

t0 <- system.time({
s0 <- !(x %in% x[duplicated(x)]);
})
print(t/t0)
stopifnot(all(s == s0))
```

[Package R.utils version 2.11.0 Index]