Runtime of NMTF training algorithms.

Shown is time in seconds until convergence of each optimization method, averaged across ten independent runs of the method. Runs that did not converge are excluded from reporting. MUR, multiplicative update rules; ALS, alternating least squares; PG, projected gradients; COD, coordinate descent. The MUR/CUD column shows a speed-up of coordinate descent relative to multiplicative update rules, i.e., the runtime of MUR divided by the runtime of COD.