PyDDM.ISF_and_DDMmatrix_theoretical_models.dTheoryExpAndBallistic_DDM
PyDDM.ISF_and_DDMmatrix_theoretical_models.dTheoryExpAndBallistic_DDM¶
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dTheoryExpAndBallistic_DDM(lagtime, amplitude, bg, tau1, s, tau2, a, Z)¶ Diffusive and ballistic motion
This model for the DDM matrix can be used to fit dynamics where there is diffusive motion as well as ballistic motion. The ballistic component is assumed to follow a Schulz distribution of velocities. This model was shown to work for characterizing the motion of bacteria 1 .
- Parameters
lagtime (array) – 1D array of the lag times
amplitude (float) – Amplitude
bg (float) – Background
tau1 (float) – Characteristic decay time for the exponential term of the ISF
s (float) – Stretching exponent for exponential term
tau2 (float) – Characteristic decay time for ballistic component
a (float) – Fraction of the dynamics that are ballistic
Z (float) – Schulz distribution number
- Returns
ddmmatrix – The DDM matrix
- Return type
array
References
- 1
Wilson, L. G. et al. Differential Dynamic Microscopy of Bacterial Motility. Phys. Rev. Lett. 106, 018101 (2011). https://doi.org/10.1103/PhysRevLett.106.018101