R: Calculate Lift Words

calclift {stm} | R Documentation

## Calculate Lift Words

### Description

A primarily internal function for calculating words according to the lift metric. We expect most users will use `labelTopics` instead.

### Usage

    calclift(logbeta, wordcounts)

### Arguments

`logbeta` | a K by V matrix containing the log probabilities of seeing word v conditional on topic k
`wordcounts` | a V length vector indicating the number of times each word appears in the corpus.

### Details

Lift is the calculated by dividing the topic-word distribution by the empirical word count probability distribution. In other words the Lift for word v in topic k can be calculated as:

Lift = β/wbar

We include this after seeing it used effectively in Matt Taddy's work including his excellent maptpx package. Definitions are given in Taddy(2012).

### References

Taddy, Matthew. 2012. "On Estimation and Selection for Topic Models." AISTATS JMLR W&CP 22

### See Also

`labelTopics`

[Package stm version 1.3.6 Index]