tff.analytics.data_processing.get_top_multi_elements

Gets the top unique word multiset from the input dataset.

tff.analytics.data_processing.get_top_multi_elements(
    dataset: tf.data.Dataset,
    max_user_contribution: int,
    string_max_bytes: Optional[int] = None
)

This method returns the max_user_contribution most common unique elements from the dataset, but returns a multiset. That is, a word will appear in the output as many times as it did in the dataset, but each unique word only counts one toward the max_user_contribution limit.

This differs from get_top_elements in that it returns a multiset rather than a set.

The input dataset must yield batched rank-1 tensors. This function reads each coordinate of the tensor as an individual element and caps the total number of elements to return. Note that the returned set of top elements will not necessarily be sorted.

dataset A tf.data.Dataset to extract top elements from. Element type must be tf.string.
max_user_contribution The maximum number of elements to keep.
string_max_bytes The maximum length (in bytes) of strings in the dataset. Strings longer than string_max_bytes will be truncated. Defaults to None, which means there is no limit of the string length.

A rank-1 Tensor containing the top max_user_contribution unique elements of the input dataset. If the total number of unique elements is less than or equal to max_user_contribution, returns the list of all unique elements.

ValueError -- If the shape of elements in dataset is not rank 1. -- If max_user_contribution is less than 1. -- If string_max_bytes is not None and is less than 1.
TypeError If dataset.element_spec.dtype must be tf.string is not tf.string.