How to generate embeddings for new candidates?

[abhinavkulkarni]

Hi,

I am been going through the code, documentation and issues to figure out how to obtain embeddings for new candidates - however I have not been able to figure this out.

I would like to add new candidates to all_entities_large.t7 file.

Firstly, the script generate_candidates.py is supposed to generate the embeddings given the token_idxs of new entities (the input parameters saved_cand_ids refers to a file that has these token_idxs), however, it is not clear how to generate these token_idxs.

So, I tried to reverse engineer generating embeddings for the following entity in entity.jsonl file:

{
  "text": " Aristotle (; \"Aristoteles\", ; 384–322 BC) was a Greek philosopher during the Classical period in Ancient Greece, the founder of the Lyceum and the Peripatetic school of philosophy and Aristotelian tradition. Along with his teacher Plato, he has been called the \"Father of Western Philosophy\". His writings cover many subjects – including physics, biology, zoology, metaphysics, logic, ethics, aesthetics, poetry, theatre, music, rhetoric, psychology, linguistics, economics, politics and government. Aristotle provided a complex synthesis of the various philosophies existing prior to him, and it was above all from his teachings that the West inherited its intellectual lexicon, as well as problems and methods of inquiry. As a result, his philosophy has exerted a unique influence on almost every form of knowledge in the West and it continues to be a subject of contemporary philosophical discussion.  Little is known about his life. Aristotle was born in the city of Stagira in Northern Greece. His father, Nicomachus, died when Aristotle was a child, and he was brought up by a guardian. At seventeen or eighteen years of age, he joined Plato's Academy in Athens and remained there until the age of thirty-seven (c. 347 BC). Shortly after Plato died, Aristotle left Athens and, at the request of Philip II of Macedon, tutored Alexander the Great beginning in 343 BC. He established a library in the Lyceum which helped him to produce many of his hundreds of books on papyrus scrolls. Though Aristotle wrote many elegant treatises and dialogues for publication, only around a third of his original",
  "idx": "https://en.wikipedia.org/wiki?curid=308",
  "title": "Aristotle",
  "entity": "Aristotle",
}

Firing up main_dense.py in interactive mode and submitting the above text produces the following named entities (persons only):

I then tried running the samples corresponding to Aristotle mentions through both context and candidate encoder parts of BiEncoder and saved the embeddings to the disk, however, they are all different from the one in all_entities_large.t7.

Are we supposed to average the embeddings of all the mentions corresponding to Aristotle entity? Or any other logic?

The BLINK paper says, the embeddings for candidates were generated by taking first 10 lines from their Wikipedia description, however, only 32 tokens are submitted to encoder to obtain an embedding, so not sure why 10 lines were selected.

Thanks!

[abhinavkulkarni]

Thanks to @ledw-2 and others from other issues, I was able to recreate embeddings for existing entities (in entity.json) using their Wikipedia description and title and was able to verify that they match those in all_entities.t7 up to the 6th decimal point.

Given a new entity title and its description, here's how to generate its embeddings:

# Load biencoder model and biencoder params just like in main_dense.py
with open(args.biencoder_config) as json_file:
    biencoder_params = json.load(json_file)
    biencoder_params["path_to_model"] = args.biencoder_model
biencoder = load_biencoder(biencoder_params)

# Read 10 entities from entity.jsonl
entities = []
count = 10
with open('./models/entity.jsonl') as f:
    for i, line in enumerate(f):
        entity = json.loads(line)
        entities.append(entity)
        if i == count-1:
            break

# Get token_ids corresponding to candidate title and description
tokenizer = biencoder.tokenizer
max_context_length, max_cand_length =  biencoder_params["max_context_length"], biencoder_params["max_cand_length"]
max_seq_length = max_cand_length
ids = []

for entity in entities:
    candidate_desc = entity['text']
    candidate_title = entity['title']
    cand_tokens = get_candidate_representation(
        candidate_desc, 
        tokenizer, 
        max_seq_length, 
        candidate_title=candidate_title
    )

    token_ids = cand_tokens["ids"]
    ids.append(token_ids)

ids = torch.tensor(ids)
torch.save(ids, path)

The file in which these ids are saved should be passed in the --saved_cand_ids param of scripts/generate_candidates.py.

Thanks to the FB team for this awesome project!

[ledw-2]

@abhinavkulkarni Thanks for the comments! I hope you find this project useful to you.😃

[amelieyu1989]

seems that we have to update and re-generate the whole entity.jsonl file in order to get .t7 file.

[abhinavkulkarni]

@amelieyu1989: No, if entity.jsonl has N entities - then all_entities.t7 file is a torch ndarry of N rows. So, you can add additional entity to entity.jsonl file and load the torch matrix, add a row and resave it.

[amelieyu1989]

I see. you mean I could get my new_encode_list = torch.cat((old_encode_list, new_entities_tokens)) could you share code if possible?

[lentikr]

@abhinavkulkarni Thank you for providing the code and assistance! I used the code you provided to generate a file called entity_token_ids_128.t7, which contains entity representations. Next, I should use the generate_candidates.py file to generate embeddings for the entities. Could you please advise me on how to set the parameters? (especially batch_size, --chunk_start and --chunk_end)

I guess it may be as follows.

python generate_candidates.py --path_to_model_config models/biencoder_wiki_large.json --path_to_model models/biencoder_wiki_large.bin --entity_dict_path models/entity1.jsonl --encoding_save_file_dir models --saved_cand_ids models/entity_token_ids_128.t7 --batch_size 512 --chunk_start 0 --chunk_end 1000000