Figure 4.

Computation speedup. Computational speed up of the stochastic parallel optimization method compared to the traditional exhaustive refinement method. Shown is the ratio of the number of iterations needed to find the optimal solution for the exhaustive and stochastic parallel optimization methods (The numbers show the fold increase in number of iterations when the exhaustive method is used). Shown are the median deviations of all 100 subtomogram alignments for the RCS method (left column) and FCS method (right column) for optimizations using a rotational search at 60° intervals (a) and 45° intervals (b), respectively.