I have read the book about machine learning. And it use gradient, but problem is D is orthogonal matrix and c is vector. I don't understand way that it gradient to c^Tc become 2c. What knowledge do I need to learn to understand it?

enter image description here

  • $\begingroup$ Gradient expands whatever you have before to make a partial derivative with respect to everything you consider to be a variable. Increasing the number of indexes by one with one new specific number in that index for that variable.. $\endgroup$ – mathreadler Oct 28 '17 at 14:59
  • 1
    $\begingroup$ It's just the gradient of $c_1^2+\dots+c_n^2$. $\endgroup$ – Hans Lundmark Oct 28 '17 at 15:07
  • $\begingroup$ I understood, thanks you. $\endgroup$ – QChí Nguyễn Oct 28 '17 at 15:14

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.