ribs.emitters.operators.IsoLineOperator¶

class ribs.emitters.operators.IsoLineOperator(lower_bounds, upper_bounds, iso_sigma, line_sigma, seed=None)[source]¶

Adds Isotropic Gaussian noise and directional noise to parents.

This operator was introduced in Vassiliades 2018.

Parameters

iso_sigma (float) – Scale factor for the isotropic distribution used to generate solutions.
line_sigma (float) – Scale factor for the line distribution used when generating solutions.
sigma (float or array-like) – Standard deviation of the Gaussian distribution. Note we assume the Gaussian is diagonal, so if this argument is an array, it must be 1D.
lower_bounds (array-like) – Upper bounds of the solution space. Passed in by emitter
upper_bounds (array-like) – Upper bounds of the solution space. Passed in by emitter
seed (int) – Value to seed the random number generator. Set to None to avoid a fixed seed.

Methods

ask(parents)

Adds Isotropic Guassian noise and directional noise to parents.

Attributes

Parent Type to be used by selector.

ask(parents)[source]¶

Adds Isotropic Guassian noise and directional noise to parents.

Parameters: parents (array-like) – (2, batch_size, solution_dim) parents[0] array of solutions selected by emitter parents[1] array of second batch of solutions passed by emitter. Used for calculating directional correlation.
Returns: (batch_size, solution_dim) array that contains batch_size mutated solutions.
Return type: numpy.ndarray

property parent_type¶

Parent Type to be used by selector.