alternate_delta_square module¶

The alternate δ² acceleration method.

class gemseo.algos.sequence_transformer.acceleration.alternate_delta_square.AlternateDeltaSquared[source]¶

Bases: SequenceTransformer

The alternate δ² acceleration method.

The method is introduced in: Isabelle Ramiere, Thomas Helfer, “Iterative residual- based vector methods to accelerate fixed point iterations”, Computers and Mathematics with Applications, (2015) eq. (48).

clear()¶

Clear the iterates.

Return type:: None

compute_transformed_iterate(iterate, residual)¶

Compute the next transformed iterate.

Parameters:

iterate (NDArray) – The iterate \(G(x_n)\).
residual (NDArray) – The associated residual \(G(x_n) - x_n\).

Returns:

The next transformed iterate \(x_{n+1}\).

Return type:

NDArray