tf.contrib.crf.crf_log_likelihood()

tf.contrib.crf.crf_log_likelihood(inputs, tag_indices, sequence_lengths, transition_params=None)

Computes the log-likehood of tag sequences in a CRF.

Args:

• inputs: A [batch_size, max_seq_len, num_tags] tensor of unary potentials to use as input to the CRF layer.
• tag_indices: A [batch_size, max_seq_len] matrix of tag indices for which we compute the log-likehood.
• sequence_lengths: A [batch_size] vector of true sequence lengths.
• transition_params: A [num_tags, num_tags] transition matrix, if available.

Returns:

• log_likelihood: A scalar containing the log-likelihood of the given sequence of tag indices.
• transition_params: A [num_tags, num_tags] transition matrix. This is either provided by the caller or created in this function.