Calculate the document prominence of each topic in a topic model

Source: R/doc_prominence.R

Calculate the document prominence of each topic in a topic model based on either the number of documents with an estimated gamma probability above a threshold or the number of documents where a topic has the highest estimated gamma probability

doc_prominence(
  topic_model,
  method = c("gamma_threshold", "largest_gamma"),
  gamma_threshold = 0.2
)

Arguments

topic_model

a fitted topic model object from one of the following: tm-class

method

a string indicating which method to use - "gamma_threshold" or "largest_gamma", the default is "gamma_threshold"

gamma_threshold

a number between 0 and 1 indicating the gamma threshold to be used when using the gamma threshold method, the default is 0.2

Value

A vector of document prominences with length equal to the number of topics in the fitted model

References

Jordan Boyd-Graber, David Mimno, and David Newman, 2014. Care and Feeding of Topic Models: Problems, Diagnostics, and Improvements. CRC Handbooks ofModern Statistical Methods. CRC Press, Boca Raton, Florida.

Examples


# Using the example from the LDA function
library(topicmodels)
data("AssociatedPress", package = "topicmodels")
lda <- LDA(AssociatedPress[1:20,], control = list(alpha = 0.1), k = 2)
doc_prominence(lda)
#> [1]  9 11