使用库LDAvis和函数createJSON的三维图形

Question

我正在寻找根据潜在Dirichlet分配功能的结果制作三维图的方法。这是我的代码：

library(lda)
example <- c("price house expectations growth positive 
         scotland report increase demand rise", "price house luxury beautiful mansion
         scotland report increase demand rise", "price house maximum growth expected 
          scotland report increase demand rise")

# converting the data into lda format 
corpus <- lexicalize(example, lower=TRUE)
corpus$documents

K=2
num.iterations=100
alpha=0.5
eta=0.5

result = lda.collapsed.gibbs.sampler(corpus$documents, K, corpus$vocab, num.iterations, 
                                     alpha,eta, initial = NULL, burnin = NULL, 
                                     compute.log.likelihood = FALSE,trace = 0L, 
                                     freeze.topics = FALSE)

有人可以帮我提供帮助来制作图表。到目前为止，这是我尝试过的：

library(LDAvis)
createJSON(as.matrix(corpus$phi), integer(corpus$term.frequency), 
           as.character(corpus$vocab), topic.proportion)

然而，我知道我犯了一个错误，但我不知道在哪里。我得到以下答案：

Error in array(x, c(length(x), 1L), if (!is.null(names(x))) list(names(x),  : 
  'data' must be of a vector type, was 'NULL'

亲切的问候，