(PECL fann >= 1.0.0)

fann_get_activation_steepnessReturns the activation steepness for supplied neuron and layer number


fann_get_activation_steepness(resource $ann, int $layer, int $neuron): float

Get the activation steepness for neuron number neuron in layer number layer, counting the input layer as layer 0.

It is not possible to get activation steepness for the neurons in the input layer.

The steepness of an activation function says something about how fast the activation function goes from the minimum to the maximum. A high value for the activation function will also give a more aggressive training.

When training neural networks where the output values should be at the extremes (usually 0 and 1, depending on the activation function), a steep activation function can be used (e.g. 1.0).

The default activation steepness is 0.5.



Neural network resource.


Layer number


Neuron number

Return Values

The activation steepness for the neuron or -1 if the neuron is not defined in the neural network, or false on error.

See Also

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