Improvements to wordcloud

[lukavdplas]

The wordcloud can be given some extra functionality to be more informative.

• [ ] Add the option for the table to show percentages instead of absolute frequencies
• [ ] If the user has entered a query or filter and is viewing a subset of the corpus, they can currently see the term frequencies in their subset. Also add the option to see frequencies relative to the whole corpus, e.g. as TF-IDF score.
• [ ] Add a setting to show bigrams/trigrams instead of unigrams. Since the wordcloud relies on a CountVectorizer, this should be trivial, though it may be problematic for the TF-IDF mentioned above.

[BeritJanssen]

For bigrams / trigrams, arguably a flat word list would be more readable than a word cloud. While of course the table view does just that, I wonder if the word cloud visualization may actually put people off.

[lukavdplas]

Here's what that would look like (in the troonredes corpus):

For the record: in our last meeting we discussed that it may be a good idea to add a horizontal bar chart layout to this visualisation. (Some other visualisations also offer different "views".) This could look like the ngram graph, but without the timeline section: