Fitted topic model.
Objects of class "LDA"
are returned by LDA()
and
of class "CTM"
by CTM()
.
Class "TopicModel"
contains
call
:Object of class "call"
.
Dim
:Object of class "integer"
; number of
documents and terms.
control
:Object of class "TopicModelcontrol"
;
options used for estimating the topic model.
k
:Object of class "integer"
; number of
topics.
terms
:Vector containing the term names.
documents
:Vector containing the document names.
beta
:Object of class "matrix"
; logarithmized
parameters of the word distribution for each topic.
gamma
:Object of class "matrix"
; parameters of
the posterior topic distribution for each document.
iter
:Object of class "integer"
; the number of
iterations made.
logLiks
:Object of class "numeric"
; the vector
of kept intermediate log-likelihood values of the corpus. See
loglikelihood
how the log-likelihood is determined.
n
:Object of class "integer"
; number of words
in the data used.
wordassignments
:Object of class
"simple_triplet_matrix"
; most probable topic for each
observed word in each document.
Class "VEM"
contains
loglikelihood
:Object of class "numeric"
; the
log-likelihood of each document given the parameters for the topic
distribution and for the word distribution of each topic is
approximated using the variational parameters and underestimates
the log-likelihood by the Kullback-Leibler divergence between the
variational posterior probability and the true posterior
probability.
Class "LDA"
extends class "TopicModel"
and has the additional
slots
loglikelihood
:Object of class "numeric"
; the
posterior likelihood of the corpus conditional on the topic
assignments is returned.
alpha
:Object of class "numeric"
; parameter of
the Dirichlet distribution for topics over documents.
Class "LDA_Gibbs"
extends class "LDA"
and has
the additional slots
seed
:Either NULL
or object of class
"simple_triplet_matrix"
; parameter for the prior
distribution of the word distribution for topics if seeded.
z
:Object of class "integer"
; topic assignments
of words ordered by terms with suitable repetition within
documents.
Class "CTM"
extends class "TopicModel"
and has the additional
slots
mu
:Object of class "numeric"
; mean of the
topic distribution on the logit scale.
Sigma
:Object of class "matrix"
;
variance-covariance matrix of topics on the logit scale.
Class "CTM_VEM"
extends classes "CTM"
and
"VEM"
and has the additional
slots
nusqared
:Object of class "matrix"
; variance of the
variational distribution on the parameter mu.
Bettina Gruen