PyDDM.ddm_calc.temporalVarianceDDMMatrix

PyDDM.ddm_calc.temporalVarianceDDMMatrix

temporalVarianceDDMMatrix(imageArray, dt, use_BH_windowing=False, quiet=False, overlap_method=2, **kwargs)

Calculates DDM matrix as a function of time at given lag time

This function calculates the DDM matrix at a given lag time. Does not average over time. This allows you to see the spread in the DDM matrix. Inspired by the analysis done in: Gao, Y., Kim, J. & Helgeson, M. E. Microdynamics and arrest of coarsening during spinodal decomposition in thermoreversible colloidal gels. Soft Matter 11, 6360–6370 (2015)

Parameters
  • imageArray (array) – 3D array of images. First dimension should be time.

  • dt (int) – lag time for which to calculate the DDM matrix (in unit of frames)

  • use_BH_windowing ({True, False}, optional) – Apply Blackman-Harris windowing to the images if True. Default is False.

  • overlap_method ({0,1,2}, optional) – Default is 1.

  • quiet ({True, False}, optional) – If True, prints updates as the computation proceeds

  • **number_differences_max (optional keyword argument) – For overlap_method of 1, sets the maximum number of differences to find for a given lag time. If `overlap_method`=1 and this keyword argument is not given, defaults to 300

Returns

  • ddm_mat (array) – The DDM matrix for given lag time. First dimension is time. Other two are the x and y wavevectors.

  • radial_avg_ddm (array) – Radial average of ddm_mat