/// <summary>
/// Calculate the derivative of the activation. It is assumed that the value
/// x, which is passed to this method, was the output from this activation.
/// This prevents this method from having to recalculate the activation, just
/// to recalculate the derivative.
/// </summary>
///
/// <param name="type"/>The type of activation.</param>
/// <param name="x"/>The activation to calculate for.</param>
/// <param name="params"/>The parameters for this activation function.</param>
/// <param name="paramOffset"/>The offset the parameters begin at.</param>
/// <returns>The derivative.</returns>
public static double CalculateActivationDerivative(int type,
double x, double[] paras, int paramOffset)
{
switch (type)
{
case ActivationFunctions.ACTIVATION_LINEAR:
return(ActivationFunctions.CalculateActivationDerivativeLINEAR(x,
paras, paramOffset));
case ActivationFunctions.ACTIVATION_TANH:
return(ActivationFunctions.CalculateActivationDerivativeTANH(x,
paras, paramOffset));
case ActivationFunctions.ACTIVATION_SIGMOID:
return(ActivationFunctions.CalculateActivationDerivativeSIGMOID(x,
paras, paramOffset));
case ACTIVATION_SOFTMAX:
return(ActivationFunctions.CalculateActivationDerivativeSOFTMAX(x,
paras, paramOffset));
case ACTIVATION_BIPOLAR:
return(ActivationFunctions.CalculateActivationDerivativeBIPOLAR(x,
paras, paramOffset));
case ACTIVATION_STEP:
return(ActivationFunctions.CalculateActivationDerivativeSTEP(x,
paras, paramOffset));
case ACTIVATION_RAMP:
return(ActivationFunctions.CalculateActivationDerivativeRAMP(x,
paras, paramOffset));
case ACTIVATION_COMPETITIVE:
return(ActivationFunctions
.CalculateActivationDerivativeCOMPETITIVE(x, paras,
paramOffset));
case ACTIVATION_SIN:
return(ActivationFunctions.CalculateActivationDerivativeSIN(x,
paras, paramOffset));
case ACTIVATION_LOG:
return(ActivationFunctions.CalculateActivationDerivativeLOG(x,
paras, paramOffset));
case ACTIVATION_GAUSSIAN:
return(ActivationFunctions.CalculateActivationDerivativeGAUSSIAN(x,
paras, paramOffset));
default:
throw new EncogEngineError("Unknown activation type: " + type);
}
}
/// <summary>
/// Calculate an activation.
/// </summary>
///
/// <param name="type"/>The type of activation.</param>
/// <param name="x"/>The input and output array. Input values are provided and thearray is modified to reflect the output.</param>
/// <param name="params"/>THe parameters needed for the calculation.</param>
/// <param name="xOffset"/>The offset into X for where we are calculating.</param>
/// <param name="xLength"/>The length of the array we are calculating.</param>
/// <param name="paramOffset"/>The parameter offset.</param>
public static void CalculateActivation(int type, double[] x,
double[] paras, int xOffset, int xLength,
int paramOffset)
{
switch (type)
{
case ActivationFunctions.ACTIVATION_LINEAR:
ActivationFunctions.CalculateActivationLINEAR(x, paras, xOffset,
xLength, paramOffset);
break;
case ActivationFunctions.ACTIVATION_TANH:
ActivationFunctions.CalculateActivationTANH(x, paras, xOffset,
xLength, paramOffset);
break;
case ActivationFunctions.ACTIVATION_SIGMOID:
ActivationFunctions.CalculateActivationSIGMOID(x, paras, xOffset,
xLength, paramOffset);
break;
case ACTIVATION_SOFTMAX:
ActivationFunctions.CalculateActivationSOFTMAX(x, paras, xOffset,
xLength, paramOffset);
break;
case ACTIVATION_BIPOLAR:
ActivationFunctions.CalculateActivationBIPOLAR(x, paras, xOffset,
xLength, paramOffset);
break;
case ACTIVATION_STEP:
ActivationFunctions.CalculateActivationSTEP(x, paras, xOffset,
xLength, paramOffset);
break;
case ACTIVATION_RAMP:
ActivationFunctions.CalculateActivationRAMP(x, paras, xOffset,
xLength, paramOffset);
break;
case ACTIVATION_COMPETITIVE:
ActivationFunctions.CalculateActivationCOMPETITIVE(x, paras,
xOffset, xLength, paramOffset);
break;
case ACTIVATION_SIN:
ActivationFunctions.CalculateActivationSIN(x, paras, xOffset,
xLength, paramOffset);
break;
case ACTIVATION_LOG:
ActivationFunctions.CalculateActivationLOG(x, paras, xOffset,
xLength, paramOffset);
break;
case ACTIVATION_GAUSSIAN:
ActivationFunctions.CalculateActivationGAUSSIAN(x, paras, xOffset,
xLength, paramOffset);
break;
default:
throw new EncogEngineError("Unknown activation type: " + type);
}
}
