Vectorize a text corpus, by turning each text into either a sequence of integers (each integer being the index of a token in a dictionary) or into a vector where the coefficient for each token could be binary, based on word count, based on tf-idf...
text_tokenizer(
num_words = NULL,
filters = "!\"#$%&()*+,-./:;<=>?@[\\]^_`{|}~\t\n",
lower = TRUE,
split = " ",
char_level = FALSE,
oov_token = NULL
)the maximum number of words to keep, based on word
frequency. Only the most common num_words words will be kept.
a string where each element is a character that will be filtered from the texts. The default is all punctuation, plus tabs and line breaks, minus the ' character.
boolean. Whether to convert the texts to lowercase.
character or string to use for token splitting.
if TRUE, every character will be treated as a token
NULL or string If given, it will be added to `word_index``
and used to replace out-of-vocabulary words during text_to_sequence calls.
The tokenizer object has the following attributes:
word_counts --- named list mapping words to the number of times they appeared
on during fit. Only set after fit_text_tokenizer() is called on the tokenizer.
word_docs --- named list mapping words to the number of documents/texts they
appeared on during fit. Only set after fit_text_tokenizer() is called on the tokenizer.
word_index --- named list mapping words to their rank/index (int). Only set
after fit_text_tokenizer() is called on the tokenizer.
document_count --- int. Number of documents (texts/sequences) the tokenizer
was trained on. Only set after fit_text_tokenizer() is called on the tokenizer.
By default, all punctuation is removed, turning the texts into
space-separated sequences of words (words maybe include the ' character).
These sequences are then split into lists of tokens. They will then be
indexed or vectorized. 0 is a reserved index that won't be assigned to any
word.
Other text tokenization:
fit_text_tokenizer(),
save_text_tokenizer(),
sequences_to_matrix(),
texts_to_matrix(),
texts_to_sequences_generator(),
texts_to_sequences()