EMM {ExtMallows} | R Documentation |

## An extended Mallows model for aggregating multiple ranking lists

### Description

It uses the extended Mallows model to aggregate multiple full/partial ranking lists.

### Usage

```
EMM(rankings, initial.method, it.max)
```

### Arguments

`rankings` |
A n by m matrix, with each column representing a ranking list, which ranks the items from the most preferred to the least preferred. For missing items, use 0 to denote them. |

`initial.method` |
the method for initializing the value of pi0, with four options: mean, median, geometric and random (the mean of three randomly sampled ranking lists). By default, initial.method="mean". |

`it.max` |
the maximum number of iterations. By default, it.max=20. |

### Value

`op.phi` |
optimal value of phi |

`op.omega` |
optimal value of omega |

`op.alpha` |
optimal value of alpha |

`op.pi0` |
optimal value of pi0, ranking the items from the most preferred to the least preferred |

`max.logL` |
maximum value of log-likelihood |

### Author(s)

Han Li, Minxuan Xu, Jun S. Liu and Xiaodan Fan

### References

An extended Mallows model for ranked data aggregation

### Examples

```
data(simu1)
res=EMM(rankings = simu1, initial.method = "mean", it.max = 20)
res$op.phi
res$op.omega
res$op.pi0
```

*ExtMallows*version 0.1.0 Index]