HEMM {ExtMallows} R Documentation

## A hierarchical extended Mallows model for aggregating multiple ranking lists

### Description

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

### Usage

HEMM(rankings, num.kappa, is.kappa.ranker, 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. num.kappa the number of over-correlated ranking groups is.kappa.ranker a list of over-correlated ranking groups, with the k-th element denoting the column numbers of the rankings that belong to the k-th group 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.phi1 optimal value of phi1, the phi value in over-correlated ranking groups 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 op.kappa optimal value of kappa, denoting 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(simu3)
res=HEMM(rankings = simu3, num.kappa = 2, is.kappa.ranker = list(1:5, 6:10),
initial.method = "mean", it.max = 20)
res$op.phi res$op.phi1
res$op.omega res$op.pi0

data(NBArankings)
res=HEMM(rankings = NBArankings, num.kappa = 1, is.kappa.ranker = list(1:6),
initial.method = "mean", it.max = 20)
res$op.omega res$op.pi0
res\$op.kappa



[Package ExtMallows version 0.1.0 Index]