R: Find the top-n matches

gower_topn {gower}

R Documentation

Find the top-n matches

Description

Find the top-n matches in y for each record in x.

Usage

gower_topn(x, y, pair_x = NULL, pair_y = NULL, n = 5, eps = 1e-08,
  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.
`n`	The top-n indices and distances to return.
`eps`	`[numeric] (optional)` Computed numbers (variable ranges) smaller than `eps` are treated as zero.
`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 from `omp::get_max_threads`.

Value

A list with two array elements: index and distance. Both have size n X nrow(x). Each ith column corresponds to the top-n best matches of x with rows in y.

Examples

# find the top 4 best matches in the iris data set with itself.
x <- iris[1:3,]
lookup <- iris[1:10,]
gower_topn(x=x,y=lookup,n=4)