SelectionFunctions

Functions that selects a subset of elements to maintain or transform, while nulling the others.

class psyneulink.core.components.functions.selectionfunctions.SelectionFunction(default_variable, params, owner, prefs, context)

Functions that selects a particular value to maintain or transform, while nulling the others.

class psyneulink.core.components.functions.selectionfunctions.OneHot(default_variable, mode=MAX_VAL, params=None, owner=None, name=None, prefs=None)

Return an array with one non-zero value.

function returns an array the same length as the first item in variable, with all of its values zeroed except one as specified by mode:

  • MAX_VAL: element with the maximum signed value in first item of variable;
  • MAX_ABS_VAL: element with the maximum absolute value;
  • MAX_INDICATOR: 1 in place of the element with the maximum signed value;
  • MAX_ABS_INDICATOR: 1 in place of the element with the maximum absolute value;
  • MIN_VAL: element with the minimum signed value in first item of variable;
  • MIN_ABS_VAL: element with the minimum absolute value;
  • MIN_INDICATOR: 1 in place of the element with the minimum signed value;
  • MIN_ABS_INDICATOR: 1 in place of the element with the minimum absolute value;
  • PROB: probabilistically chosen element based on probabilities passed in second item of variable;
  • PROB_INDICATOR: same as PROB but chosen item is assigned a value of 1.
Parameters:
  • variable (2d np.array : default class_defaults.variable) – First (possibly only) item specifies a template for the array to be transformed; if mode is PROB then a 2nd item must be included that is a probability distribution with same length as 1st item.
  • mode (MAX_VAL, MAX_ABS_VAL, MAX_INDICATOR, MAX_ABS_INDICATOR, MIN_VAL, MIN_ABS_VAL, MIN_INDICATOR,) –
  • PROB or PROB_INDICATOR (MIN_ABS_INDICATOR,) – specifies the nature of the single non-zero value in the array returned by function (see mode for details).
  • params (Dict[param keyword: param value] : default None) – a parameter dictionary that specifies the parameters for the function. Values specified for parameters in the dictionary override any assigned to those parameters in arguments of the constructor.
  • bounds (None) –
  • owner (Component) – component to which to assign the Function.
  • name (str : default see name) – specifies the name of the Function.
  • prefs (PreferenceSet or specification dict : default Function.classPreferences) – specifies the PreferenceSet for the Function (see prefs for details).
variable

number or np.array – 1st item contains value to be transformed; if mode is PROB, 2nd item is a probability distribution, each element of which specifies the probability for selecting the corresponding element of the 1st item.

mode

MAX_VAL, MAX_ABS_VAL, MAX_INDICATOR, MAX_ABS_INDICATOR, MIN_VAL, MIN_ABS_VAL, MIN_INDICATOR,

MIN_ABS_INDICATOR, PROB or PROB_INDICATOR

determines the nature of the single non-zero value in the array returned by function (see above for options).

owner

Componentcomponent to which the Function has been assigned.

name

str – the name of the Function; if it is not specified in the name argument of the constructor, a default is assigned by FunctionRegistry (see Naming for conventions used for default and duplicate names).

prefs

PreferenceSet or specification dict : Function.classPreferences – the PreferenceSet for function; if it is not specified in the prefs argument of the Function’s constructor, a default is assigned using classPreferences defined in __init__.py (see PreferenceSet for details).

function(variable=None, execution_id=None, params=None, context=None)
Parameters:
  • variable (2d np.array : default class_defaults.variable) – 1st item is an array to be transformed; if mode is PROB, 2nd item must be an array of probabilities (i.e., elements between 0 and 1) of equal length to the 1st item.
  • params (Dict[param keyword: param value] : default None) – a parameter dictionary that specifies the parameters for the function. Values specified for parameters in the dictionary override any assigned to those parameters in arguments of the constructor.
Returns:

array with single non-zero value – specified by mode.

Return type:

np.array