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Using the range option

Grossfield Lab edited this page Aug 12, 2020 · 2 revisions

When analyzing a trajectory, it's common to not want to use all of the frames. Nearly all LOOS tools provide the --skip and --stride options, to let you ignore the beginning of the trajectory and to step through frames with a step size greater than 1. However, for finer control some tools also provide the --range option, which provides more functionality.

The general format is --range first:stride:last, based on the format used in MATLAB. Note that unlike numpy or python, frame last is included. The behavior is best explained by examples:

  • --range 10 would skip frames 0-9.
  • --range 10:20 would analyze frames (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
  • --range 10:2:20 would analyze frames (10, 12, 14, 16, 18, 20)

You can also combine ranges together using commas:

  • --range "10:2:20,32:5:48" would select out frames (10, 12, 14, 16, 18, 20, 32, 37, 42, 47)