# concordance: Compute Concordance Matrix In clusterCrit: Clustering Indices

## Description

`concordance` calculates the concordance matrix between two partitions of the same data.

## Usage

 `1` ``` concordance(part1, part2) ```

## Arguments

 `part1` `[vector]` : the first partition vector. `part2` `[vector]` : the second partition vector.

## Details

Given two partitions, the function `concordance` calculates the number of pairs classified as belonging or not belonging to the same cluster with respect to partitions `part1` or `part2`.

## Value

A 2x2 matrix of the form :

 ```1 2 3 4 5``` ``` | P1 | P2 | ____________________ P1 | Nyy | Nyn | P2 | Nny | Nnn | ____________________ ```

where

• `Nyy` is the number of points belonging to the same cluster both in `part1` and `part2`

• `Nyn` is the number of points belonging to the same cluster in `part1` but not in `part2`

• `Nny` is the number of points belonging to the same cluster in `part2` but not in `part1`

• `Nnn` is the number of points not belonging to the same cluster both in `part1` and `part2`

## Author

Bernard Desgraupes
bernard.desgraupes@u-paris10.fr
University of Paris Ouest - Nanterre
Lab Modal'X (EA 3454)

`extCriteria`, `intCriteria`.

## Examples

 ```1 2 3 4 5 6``` ```# Generate two artificial partitions part1<-sample(1:3,150,replace=TRUE) part2<-sample(1:5,150,replace=TRUE) # Compute the table of concordances and discordances concordance(part1,part2) ```

### Example output

```     y    n
y  768 3034
n 1471 5902
```

clusterCrit documentation built on May 2, 2019, 3:22 p.m.