Package topo :: Package transferfn :: Module basic :: Class Sigmoid

Class Sigmoid

Sigmoidal (logistic) transfer function: 1/(1+exp-(r*x+k)).

As defined in Jochen Triesch, ICANN 2005, LNCS 3696 pp. 65-70. The parameters control the growth rate (r) and the x position (k) of the exponential.

This function is a special case of the GeneralizedLogistic function, with parameters r=r, l=0, u=1, m=-k/2r, and b=1. See Richards, F.J. (1959), A flexible growth function for empirical use. J. Experimental Botany 10: 290--300, 1959. http://en.wikipedia.org/wiki/Generalised_logistic_curve

Nested Classes

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Inherited from param.parameterized.Parameterized: __metaclass__

Instance Methods

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__call__(self, x)

source code

Inherited from param.parameterized.Parameterized: __getstate__, __init__, __repr__, __setstate__, __str__, debug, defaults, force_new_dynamic_value, get_param_values, get_value_generator, inspect_value, message, print_param_values, script_repr, set_default, set_dynamic_time_fn, set_param, state_pop, state_push, verbose, warning

Inherited from param.parameterized.Parameterized (private): _add_parameter, _instantiate_param, _set_name, _setup_params

Inherited from object: __delattr__, __format__, __getattribute__, __hash__, __new__, __reduce__, __reduce_ex__, __setattr__, __sizeof__, __subclasshook__

Class Methods

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Inherited from param.parameterized.Parameterized: params, print_param_defaults

Class Variables

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r = param.Number(default= 1, doc= "Parameter controlling the g...
Parameter controlling the growth rate

k = param.Number(default= 0, doc= "Parameter controlling the x...
Parameter controlling the x-postion

name = <param.parameterized.String object at 0xb5891ec>
String identifier for this object.

Inherited from base.functionfamily.TransferFn: norm_value

Inherited from param.parameterized.Parameterized: print_level

Properties

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Inherited from object: __class__

Method Details

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call(self, x)
(Call operator)

source code

Overrides: base.functionfamily.TransferFn.__call__

Class Variable Details

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r

Parameter controlling the growth rate

Value:

param.Number(default= 1, doc= "Parameter controlling the growth rate")

k

Parameter controlling the x-postion

Value:

param.Number(default= 0, doc= "Parameter controlling the x-postion")

Class Sigmoid

__call__(self, x) (Call operator)

r

k

call(self, x)
(Call operator)