simulations

This module include functions for running bead trajectory simulations.

tweezepy.simulations.downsampled_trace(gamma=1e-05, kappa=None, fsample=100, N=10240, seed=None)

Simulates and downsamples trace.

Parameters
  • gamma (float, optional) – Stokes dissipation in pNs/nm^2, by default 1.e-5

  • kappa (float, optional) – Spring constant in pN/nm, by default None

  • fsample (int, optional) – Sampling frequency in Hz, by default 100

  • N (int, optional) – Number of downsampled bead positions, by default 10240

  • seed (int, optional) – Random seed, by default None

Returns

xtrace_ds – Array of bead positions.

Return type

numpy.array

tweezepy.simulations.simulate_trace(gamma=1e-05, kappa=None, fsim=400, sim_points=10240, seed=None)

Takes parameters and gives a simulated bead trajectory.

\[\Delta x = \frac{\Delta t}{\gamma}\left(\sqrt{\frac{2\gamma k_BT}{dt}} F_L-\kappa x_{i-1}\right)\]
\[x_i = x_{i-1}+dx\]
Parameters
  • gamma (float, optional) – Stokes dissipation in pNs/nm^2, by default 1.e-5

  • kappa (float, optional) – Spring constant in pN/nm, by default None

  • fsim (int, optional) – Simulation frequency in Hz, by default 100

  • sim_points (int, optional) – Number of bead positions, by default 10240

  • seed (int, optional) – Random seed, by default None

Returns

xtrace – Array of bead positions.

Return type

array