Object Type:	sigmoid

Description:	

Computes the sigmoidal transformation of the input and places the result in
'state'.  The equation being applied is

        state = amplitude*(tanh(gain*(input - thresh)) + 1)/2.0

This gives a ``squashing'' function which is commonly used in connectionist
models as an approximation to the relation between the amount of synaptic
input to a cell and its firing rate.

Author:		M. Wilson, Caltech (6/88)

------------------------------------------------------------------------------

ELEMENT PARAMETERS

Data Structure:	sigmoid_type  [in src/buffer/buf_struct.h]

Size:		116 bytes

Fields:		thresh
		amplitude
		input
		state
		gain

------------------------------------------------------------------------------

SIMULATION PARAMETERS

Function:	SigmoidEvent  [in src/buffer/sigmoid.c]

Classes:	buffer
		segment

Actions:	PROCESS RESET COPY CREATE

Messages:	INPUT	input
		THRESH	threshold
		GAIN	gain 
		AMP	amplitude 

------------------------------------------------------------------------------

Notes:		

Example:	Scripts/examples/sigmoid.

See also:	

