How To Plot Keras Activation Functions In A Notebook

I wanted to plot all Keras activation functions but some of them are not working. i.e. linear throws an error: AttributeError: 'Series' object has no attribute 'eval' which is w

Solution 1:

That's because the linear activation returns the input without any modifications:

deflinear(x):
    """Linear (i.e. identity) activation function.
    """return x

Since you are passing a Pandas Series as input, the same Pandas Series will be returned and therefore you don't need to use K.eval():

df["linear"] = activations.linear(df["activation"])

As for the selu activation, you need to reshape the input to (n_samples, n_output):

df["selu"] = K.eval(activations.selu(df["activation"].values.reshape(-1,1)))

And as for the hard_sigmoid activation, its input should be explicitly a Tensor which you can create using K.variable():

df["hard_sigmoid"] = K.eval(activations.hard_sigmoid(K.variable(df["activation"].values)))

Further, exponential activation works as you have written and there is no need for modifications.