# krypy.recycling.factories - deflation vector factories¶

class krypy.recycling.factories.RitzFactory(subset_evaluator, subsets_generator=None, mode='ritz', print_results=None)

Factory of Ritz vectors for automatic recycling.

Parameters: subset_evaluator – an instance of _RitzSubsetEvaluator that evaluates a proposed subset of Ritz vectors for deflation. subsets_generator – (optional) an instance of _RitzSubsetsGenerator that generates lists of subsets of Ritz vectors for deflation. print_results – (optional) may be one of the following: None: nothing is printed. ’number’: the number of selected deflation vectors is printed. ’values’: the Ritz values corresponding to the selected Ritz vectors are printed. ’timings’: the timings of all evaluated subsets of Ritz vectors are printed.
get(deflated_solver)
class krypy.recycling.factories.RitzFactorySimple(mode='ritz', n_vectors=0, which='sm')

Selects a fixed number of Ritz or harmonic Ritz vectors with respect to a prescribed criterion.

Parameters: mode – See mode parameter of Ritz. n_vectors – number of vectors that are chosen. Actual number of deflation vectors may be lower if the number of Ritz pairs is less than n_vectors. which – the n_vectors Ritz vectors are chosen such that the corresponding Ritz values are the ones with lm: largest magnitude. sm: smallest magnitude. lr: largest real part. sr: smallest real part. li: largest imaginary part. si: smallest imaginary part. smallest_res: smallest Ritz residual norms.
get(solver)
class krypy.recycling.factories.UnionFactory(factories)

Combine a list of factories.

Parameters: factories – a list of factories derived from _DeflationVectorFactory.
get(solver)
class krypy.recycling.factories._DeflationVectorFactory

Abstract base class for selectors.

get(solver)

Get deflation vectors.

Returns: numpy.array of shape (N,k)