textmineR (version 3.0.4)

SummarizeTopics: Summarize topics in a topic model

Description

Create a data frame summarizing the contents of each topic in a model

Usage

SummarizeTopics(model)

Arguments

model

A list (or S3 object) with three named matrices: phi, theta, and gamma. These conform to outputs of many of textmineR's native topic modeling functions such as FitLdaModel.

Value

An object of class data.frame with 6 columns: 'topic' is the name of the topic, 'prevalence' is the rough prevalence of the topic in all documents across the corpus, 'coherence' is the probabilistic coherence of the topic, 'top_terms_phi' are the top 5 terms for each topic according to P(word|topic), 'top_terms_gamma' are the top 5 terms for each topic according to P(topic|word).

Details

'prevalence' is normalized to sum to 100. If your 'theta' matrix has negative values (as may be the case with an LSA model), a constant is added so that the least prevalent topic has a prevalence of 0.

'coherence' is calculated using CalcProbCoherence.

'label' is assigned using the top label from LabelTopics. This requires an "assignment" matrix. This matrix is like a "theta" matrix except that it is binary. A topic is "in" a document or it is not. The assignment is made by comparing each value of theta to the minimum of the largest value for each row of theta (each document). This ensures that each document has at least one topic assigned to it.

Examples

# NOT RUN {
SummarizeTopics(nih_sample_topic_model)
# }