Topic model topic coherence¶
| Path | pimlico.modules.gensim.coherence |
| Executable | yes |
Compute topic coherence.
Takes input as a list of the top words for each topic. This can be produced from various types of topic model, so they can all be evaluated using this method.
Also requires a corpus from which to compute the PMI statistics. This should typically be a different corpus to that on which the model was trained.
For now, this just computes statistics and outputs them to a text file, and also outputs a single number representing the mean topic coherence across topics.
This module does not support Python 2, so can only be used when Pimlico is being run under Python 3
Inputs¶
| Name | Type(s) |
|---|---|
| topics_top_words | topics_top_words |
| corpus | grouped_corpus <TokenizedDocumentType> |
| vocab | dictionary |
Outputs¶
| Name | Type(s) |
|---|---|
| output | named_file |
| mean_coherence | numeric_result |
Options¶
| Name | Description | Type |
|---|---|---|
| coherence | Coherence measure to use, selecting from one of Gensim’s pre-defined measures: ‘u_mass’, ‘c_v’, ‘c_uci’, ‘c_npmi’. Default: ‘u_mass’ | ‘u_mass’, ‘c_v’, ‘c_uci’ or ‘c_npmi’ |
| window_size | Size of the window to be used for coherence measures using boolean sliding window as their probability estimator. For ‘u_mass’ this doesn’t matter. If None, the default window sizes are used which are: ‘c_v’ - 110, ‘c_uci’ - 10, ‘c_npmi’ - 10. | int |
Example config¶
This is an example of how this module can be used in a pipeline config file.
[my_topic_coherence_module]
type=pimlico.modules.gensim.coherence
input_topics_top_words=module_a.some_output
input_corpus=module_a.some_output
input_vocab=module_a.some_output
This example usage includes more options.
[my_topic_coherence_module]
type=pimlico.modules.gensim.coherence
input_topics_top_words=module_a.some_output
input_corpus=module_a.some_output
input_vocab=module_a.some_output
coherence=u_mass
window_size=0
Test pipelines¶
This module is used by the following test pipelines. They are a further source of examples of the module’s usage.