frame_lag¶
-
mdtools.check.
frame_lag
(lag, every, n_frames_tot=None, allow_zero=False, verbose=True)[source]¶ Check if a frame lag (‘lag time’) is chosen properly.
Check if a frame lag (‘lag time’) is chosen properly with respect to the total number of frames in the trajectory and the interval between frames that are/were actually read.
The frame lag must meet the following requirements:
Must be greater than zero (if allow_zero is
True
, zero is also possible)Must not be greater than n_frames_tot (if supplied).
Must be an integer multiple of every.
- Parameters
lag (int) – The frame lag, e.g. the number of frames between restarting points.
every (int) – Intervall used while reading the trajectory, i.e. only every n-th frame of the trajectory is/was actually read.
n_frames_tot (int, optional) – The total number of frames in the trajectory.
allow_zero (bool, optional) – If
True
, lag can also be zero.verbose (bool, optional) – If
True
(default), any changes to lag are printed to standard output.
- Returns
lag (int) – The input or a corrected value.
effective_lag (int) – An effective frame lag. If e.g. only every tenth frame of the trajectory is read and you want a frame lag of fifty, the effective frame lag is five.
See also
mdtools.check.frame_slicing()
Check if the input parameters are suitable for slicing MDAnalysis trajectories
mdtools.check.block_averaging()
Check if the number of blocks for block averaging is chosen properly
mdtools.check.time_step()
Check whether all frames in a MDAnalysis trajectory have the same
time step