title: How to create PSS and SS activation functions in Keras
body: <p>I'm using keras with tensorflow backend. My goal is to add my custom activation functions (PSS, SS) but I don't know how can i implement them.</p>
  <p><a href="https://i.stack.imgur.com/YOUNo.png" rel="nofollow noreferrer">Positive Smooth Staircase (PSS) activation function</a></p>
  <p>Where n is number of output labels, w is a constant.</p>
  <p><a href="https://i.stack.imgur.com/8RU1J.png" rel="nofollow noreferrer">Smooth Staircase (SS) activation function</a></p>
  <p>Where n is number of output labels (output neurons), c is a constant.</p>