Comparing LDA output
We've only run a single LDA with a specific number of topics. The tidied output from that model, lda_out_tidy, has been loaded along with dtm_twitter in your workspace. Now run LDA with 3 topics and compare the outputs.
> lda_out_tidy
# A tibble: 35,928 x 3
topic term beta
<int> <chr> <dbl>
1 1 flight 0.0343
2 1 time 0.0102
3 2 service 0.00882
4 1 plane 0.00688
5 1 trip 0.00614
6 2 customer 0.00604
7 1 delayed 0.00596
8 2 airline 0.00593
9 1 hours 0.00532
10 1 day 0.00499
# ... with 35,918 more rows
This exercise is part of the course
Introduction to Text Analysis in R
Exercise instructions
- Run an LDA with 3 topics and a Gibbs sampler (this may take 10 or more seconds).
- Tidy the matrix of word probabilities.
- Arrange the topics by word probabilities in descending order.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Run an LDA with 3 topics and a Gibbs sampler
lda_out2 <- ___(
___,
___,
___,
control = list(seed = 42)
)
# Tidy the matrix of word probabilities
lda_topics2 <- ___ %>%
___(___)
# Arrange the topics by word probabilities in descending order
___ %>%
___(___)