Unwhich {DescTools} | R Documentation |

## Inverse Which

### Description

The inverse function to `which`

creates a logical
vector/matrix from indices.

### Usage

```
Unwhich(idx, n = max(idx), useNames = TRUE)
```

### Arguments

`idx` |
the indices as returned by |

`n` |
integer, the length of the original vector. This must not be less than |

`useNames` |
logical, determining if the names of the indices should be preserved. |

### Value

a logical vector of the length n, with `TRUE`

on the positions `i`

.

### Author(s)

Nick Sabbe

### References

https://stackoverflow.com/questions/7659833/inverse-of-which

### See Also

### Examples

```
ll <- c(TRUE, FALSE, TRUE, NA, FALSE, FALSE, TRUE)
names(ll) <- letters[seq(ll)]
i <- which(ll)
# back again (loosing the names of the FALSEs)
Unwhich(i, length(ll))
```

[Package

*DescTools*version 0.99.55 Index]