title: Numpy: How does np.abs actually work under the hood?
body: <p>I'm trying to implement my own absolute function for gonum dense vectors in Go. I'm wandering if there's a better way of getting the absolute value of an array than squaring and then square rooting?</p>
  
  <p>My main issue is that I've had to implement my own element wise Newtonian square-root function on these vectors and there's a balance between implementation speed and accuracy. If I could avoid using this square-root function I'd be happy.</p>