4 ms·

So, how does twitter uses Jacobian?

• jordigh 9y ago
  A Jacobian is often used in optimisation. In machine learning, optimisation is often relabelled "learning", because they're finding the minimum of a cost function, also sometimes called an error function. You may have heard of backpropagation. Backprop is merely a convenient way to compute the Jacobian of a feed-forward neural network. The Jacobian computed by backprop is then used to pick a line search direction to minimise the network's error. Put it another way, a Jacobian is kind of a multidimensional gradient. It tells you in which multidimensions a function is changing the most rapidly.
  • dnautics 9y ago
    yeah but is most of twitter really using that?
    • dxbydt 9y ago
      no, but most of twitter isn't using knowledge of katy perry's whereabouts either. Storing garbage info like katy perry kim kardashian etc. in your brain, in my humble opinion, is a tax on your cognition - one pays that tax by being ignorant of elementary methods like fourier transform or multivariable calculus or eigenvalues or trig integrals or T distribution or you get the idea...
      • dnautics 9y ago
        I'm quite good at math and found your anecdote funny (yes, I know what a jacobian and a hessian are, and give have lectures on using the fourier transform to professional scientists), but honestly most people, including coders, don't need that, and their lives are not bettered by knowing these things. It is a lot bit pretentious, and not humble at all, to judge people for keeping 'garbage' information.
        • dxbydt 9y ago
          I have no opinion on what others should deposit in their brains. Am just saying personally if I start keeping track of garbage info like kate and kim, I tend to forget my trig integrals. I have empirically verified that over time. So given a choice, I choose to be blissfully unaware of these cultural cues, so I can store stuff I deem more useful