cma.transformations.ConstRandnShift

class documentation

class ConstRandnShift(object):

ConstRandnShift()(x) adds a fixed realization of stddev * randn(len(x)) to the vector x.

By default, the realized shift is the same for each instance of ConstRandnShift, see seed argument. This class is used in class Shifted as default transformation.

See Also
class `Shifted`

Method	`__call__`	return "shifted" `x - shift`
Method	`__init__`	with `seed=None` each instance realizes a different shift
Method	`get`	return shift applied to `zeros(dimension)`
Instance Variable	`seed`	Undocumented
Instance Variable	`stddev`	Undocumented
Instance Variable	`_xopt`	Undocumented

def __call__(self, x): ¶

return "shifted" x - shift

def __init__(self, stddev=3, seed=1): ¶

with seed=None each instance realizes a different shift

def get(self, dimension): ¶

return shift applied to zeros(dimension)

>>> import numpy as np, cma
>>> s = cma.transformations.ConstRandnShift()
>>> assert all(s(-s.get(3)) == np.zeros(3))
>>> assert all(s.get(3) == s(np.zeros(3)))

seed = ¶

Undocumented

stddev = ¶

Undocumented

_xopt: dict = ¶

Undocumented