sigmoidalUnit.m, sigmoidalUnitDeriv.m, valueUnit.m, valueUnit2Deriv.m, and valueUnitDeriv.m

Modules that only calculate the activation functions of the corresponding type of unit. They are called from the training functions described, with the use of evaluation¹² of set of variables like actFunc , defined in Section 4.1.5 which hold the name of the script file to call for the associated activation function (or derivative) of a unit. (See variable unitType  in Section 4.1.1 for possible activation functions supported in this software.)

The function names which have -Deriv and -2Deriv as ending compute the first, and the second derivative  of the activation function , respectively.

The activation functions (but not the derivative functions) also return some other useful information when given specific parameters, complying with MATLAB's  activation function conventions. These are the name of the associated derivative function, the version of NN Toolbox , and the range of the input and output.