Re:An overview of gradient descent optimization algorithms
by partykid92 on Wednesday November 09, 2016 @04:43PM
(#12914968)
quasi newton methods are not square in the dimension of the problem (think limited memory L-BFGS), and can be run in linear time. In my experience, however, they're 2-3 times slower than regular methods like ADAM.
I'm not sure conjugate gradient methods are used much, due to the non-convexity of the merit functions, and hard constraints aren't used much either.