tf.compat.v1.nn.sufficient_statistics

Calculate the sufficient statistics for the mean and variance of x.

tf.compat.v1.nn.sufficient_statistics(
    x, axes, shift=None, keep_dims=None, name=None, keepdims=None
)

These sufficient statistics are computed using the one pass algorithm on an input that's optionally shifted. See: https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Computing_shifted_data

For example:

t = [[1, 2, 3], [4, 5, 6]]
sufficient_statistics(t, [1])
(<tf.Tensor: shape=(), dtype=int32, numpy=3>, <tf.Tensor: shape=(2,),
dtype=int32, numpy=array([ 6, 15], dtype=int32)>, <tf.Tensor: shape=(2,),
dtype=int32, numpy=array([14, 77], dtype=int32)>, None)
sufficient_statistics(t, [-1])
(<tf.Tensor: shape=(), dtype=int32, numpy=3>, <tf.Tensor: shape=(2,),
dtype=int32, numpy=array([ 6, 15], dtype=int32)>, <tf.Tensor: shape=(2,),
dtype=int32, numpy=array([14, 77], dtype=int32)>, None)

x A Tensor.
axes Array of ints. Axes along which to compute mean and variance. As in Python, the axes can also be negative numbers. A negative axis is interpreted as counting from the end of the rank, i.e., axis + rank(values)-th dimension.
shift A Tensor containing the value by which to shift the data for numerical stability, or None if no shift is to be performed. A shift close to the true mean provides the most numerically stable results.
keep_dims produce statistics with the same dimensionality as the input.
name Name used to scope the operations that compute the sufficient stats.
keepdims Alias for keep_dims.

Four Tensor objects of the same type as x:

  • the count (number of elements to average over).
  • the (possibly shifted) sum of the elements in the array.
  • the (possibly shifted) sum of squares of the elements in the array.
  • the shift by which the mean must be corrected or None if shift is None.