modea.Utils module¶

A collection of utilities for internal use by this package. Besides some trivial functions, this mainly includes the ESFitness class definition.

class modea.Utils.ESFitness(fitnesses=None, target=1e-08, min_fitnesses=None, min_indices=None, num_successful=None, ERT=None, FCE=inf, std_dev_ERT=None, std_dev_FCE=None)¶

Bases: object

Object to calculate and store the fitness measure for an ES and allow easy comparison. This measure consists of both the always available Fixed Cost Error (FCE) and the less available but more rigorous Expected Running Time (ERT).

All parameters are listed as optional, but at least one of the following combinations have to be given to obtain FCE/ERT values.

>>> ESFitness(fitnesses=fitnesses)
>>> ESFitness(min_fitnesses=min_fitnesses, min_indices=min_indices, num_successful=num_successful)
>>> ESFitness(ERT=ERT, FCE=FCE)

If fitnesses is specified, all other parameters other than target are ignored and everything is calculated from that. Otherwise, ERT and FCE are calculated from min_fitnesses, min_indices and num_successful. Only if none of these are specified, the direct ERT and FCE values are stored (together with their corresponding std_dev_ values if specified)

Parameters:

fitnesses – Nested lists: A list of the fitness progression for each run
target – What value to use as target for calculating ERT. Default set in Config
min_fitnesses – Single list containing the minimum value of the fitnesses list (if given instead)
min_indices – Single list containing the index in the fitnesses list where the minimum was found
num_successful – Integer to simply track how many of the runs reached the target
ERT – Estimated Running Time
FCE – Fixed Cost Error
std_dev_ERT – Standard deviation corresponding to the ERT value
std_dev_FCE – Standard deviation corresponding to the FCE value

modea.Utils.create_bounds(values, percentage)¶

For a given set of floating point values, create an upper and lower bound. Bound values are defined as a percentage above/below the given values.

Parameters:	values – List of floating point input values. percentage – The percentage value to use, expected as a fraction in the range (0, 1).
Returns:	Tuple (u_bound, l_bound), each a regular list.

modea.Utils.getBitString(opts)¶

Reverse of getOpts, transforms options dictionary to integer ‘bitstring’

Parameters:	opts – Dictionary with option names and the chosen option
Returns:	A list of integers that serve as index for the options tuple

modea.Utils.getFitness(individual)¶

Function that can be used as key when sorting

Parameters:	individual – Some object of one of the classes from the `Individual` module
Returns:	Fitness attribute of the given individual object

modea.Utils.getFullOpts(opts)¶

Ensures that an options dictionary actually contains all options that have been defined. Any missing options are given default values inline.

Parameters:	opts – Dictionary to be checked for option names and the chosen option

modea.Utils.getOpts(bitstring)¶

Transformation from integer ‘bitstring’ to options dictionary

Parameters:	bitstring – List/array of integers that serve as index for the options tuple
Returns:	Dictionary with all option names and the chosen option

modea.Utils.getPrintName(opts)¶

Create a human-readable name from an options dictionary

Parameters:	opts – Dictionary to be checked for option names and the chosen option
Returns:	Human-readable string listing all active CMA-ES options for the given dictionary

modea.Utils.getVals(init_values)¶

Transformation from real numbered vector to values dictionary

Parameters:	init_values – List/array of real values that serve as initial values for parameters
Returns:	Dictionary containing name-indexed initial parameter values

modea.Utils.guaranteeFolderExists(path_name)¶: Make sure the given path exists after this call

modea.Utils.intToRepr(integer)¶

Dencode the ES-structure from a single integer back to the mixed base-2 and 3 representation. Reverse of reprToInt()

>>> intToRepr(93)
>>> [0,0,0,0,0,1,0,1,0,1,0]

Parameters:	integer – Integer (e.g. outoutput from reprToInt() )
Returns:	String consisting of all structure choices concatenated,

modea.Utils.reprToInt(representation)¶

Encode the ES-structure representation to a single integer by converting it to base-10 as if it is a mixed base-2 or 3 number. Reverse of intToRepr()

>>> reprToInt([0,0,0,0,0,1,0,1,0,1,0])
>>> 93

Parameters:	representation – Iterable; the genotype of the ES-structure
Returns:	String consisting of all structure choices concatenated,

modea.Utils.reprToString(representation)¶

Function that converts the structure parameters of a given ES-structure representation to a string

>>> reprToInt([0,0,0,0,0,1,0,1,0,1,0])
>>> '00000101010'

Parameters:	representation – Iterable; the genotype of the ES-structure
Returns:	String consisting of all structure choices concatenated, e.g.: `00000101010`