2015

Stop Wasting My Gradients: Practical SVRG

Babanezhad, Reza, Ahmed, Mohamed Osama, Virani, Alim et al.

Understand

We present and analyze several strategies for improving the performance of stochastic variance-reduced gradient (SVRG) methods.

  • We first show that the convergence rate of these methods can be preserved under a decreasing sequence of errors in the control variate, and use this to derive variants of SVRG that use growing-batch strategies to reduce the number of gradient calculations required in the early iterations.
  • We further (i) show how to exploit support vectors to reduce the number of gradient computations in the later iterations, (ii) prove that the commonly-used regularized SVRG iteration is justified and improves the convergence rate, (iii) consider alternate mini-batch selection strategies, and (iv) consider the generalization error of the method.

Reading the bibliography…