# gower_dist

##### Gower's distance

Compute Gower's distance, pairwise between records in two data sets `x`

and `y`

. Records from the smallest data set are recycled over.

##### Usage

```
gower_dist(x, y, pair_x = NULL, pair_y = NULL, eps = 1e-08,
weights = NULL, ignore_case = FALSE,
nthread = getOption("gd_num_thread"))
```

##### Arguments

- x
`[data.frame]`

- y
`[data.frame]`

- pair_x
`[numeric|character] (optional)`

Columns in`x`

used for comparison. See Details below.- pair_y
`[numeric|character] (optional)`

Columns in`y`

used for comparison. See Details below.- eps
`[numeric] (optional)`

Computed numbers (variable ranges) smaller than`eps`

are treated as zero.- weights
`[numeric] (optional)`

A vector of weights of length`ncol(x)`

that defines the weight applied to each component of the gower distance.- ignore_case
`[logical]`

Toggle ignore case when neither`pair_x`

nor`pair_y`

are user-defined.- nthread
Number of threads to use for parallelization. By default, for a dual-core machine, 2 threads are used. For any other machine n-1 cores are used so your machine doesn't freeze during a big computation. The maximum nr of threads are determined using

`omp_get_max_threads`

at C level.

##### Details

There are three ways to specify which columns of `x`

should be compared
with what columns of `y`

. The first option is do give no specification.
In that case columns with matching names will be used. The second option
is to use only the `pairs_y`

argument, specifying for each column in `x`

in order, which column in `y`

must be used to pair it with (use `0`

to skip a column in `x`

). The third option is to explicitly specify the
columns to be matched using `pair_x`

and `pair_y`

.

##### Value

A `numeric`

vector of length `max(nrow(x),nrow(y))`

.
When there are no columns to compare, a message is printed and both
`numeric(0)`

is returned invisibly.

##### Note

Gower (1971) originally defined a similarity measure (\(s\), say) with values ranging from 0 (completely dissimilar) to 1 (completely similar). The distance returned here equals \(1-s\).

##### References

Gower, John C. "A general coefficient of similarity and some of its properties." Biometrics (1971): 857-871.

##### See Also

*Documentation reproduced from package gower, version 0.2.1, License: GPL-3*