tfp.math.bracket_root

Finds bounds that bracket a root of the objective function.

tfp.math.bracket_root(
    objective_fn,
    dtype=tf.float32,
    num_points=512,
    name='bracket_root'
)

This method attempts to return an interval bracketing a root of the objective function. It evaluates the objective in parallel at num_points locations, at exponentially increasing distance from the origin, and returns the first pair of adjacent points [low, high] such that the objective is finite and has a different sign at the two points. If no such pair was observed, it returns the trivial interval [np.finfo(dtype).min, np.finfo(dtype).max] containing all float values of the specified dtype. If the objective has multiple roots, the returned interval will contain at least one (but perhaps not all) of the roots.

Args
objective_fn	Python callable for which roots are searched. It must be a continuous function that accepts a scalar Tensor of type dtype and returns a Tensor of shape batch_shape.
dtype	Optional float dtype of inputs to objective_fn. Default value: tf.float32.
num_points	Optional Python int number of points at which to evaluate the objective. Default value: 512.
name	Python str name given to ops created by this method.

Returns
low	Float Tensor of shape batch_shape and dtype dtype. Lower bound on a root of objective_fn.
high	Float Tensor of shape batch_shape and dtype dtype. Upper bound on a root of objective_fn.