acf

libra_py.acf.acf_mat(data, dt, opt=0)[source]

Compute the autocorrelation function of the given data set

Parameters
  • data (list of MATRIX(ndof, 1) objects) – sequence of real-valued ndof-dimensional vectors

  • dt (double) – time distance between the adjacent data points [units: general]

  • opt (int) –

    selector of the convention to to compute ACF

    • 0 : the chemist convention, (1/(N-h)) Sum_{t=1,N-h} (Y[t]*Y[t+h])

    • 1 : the statistician convention, (1/N) Sum_{t=1,N-h} (Y[t]*Y[t+h])

Returns

(T, nautocorr, autocorr), where:

T (list of sz doubles ): lag time scale for the ACF [units: same as for dt] nautocorr (list of sz doubles ): normalized ACF autocorr (list of sz doubles ): un-normalized ACF

Return type

tuple

SeeAlso:

https://www.itl.nist.gov/div898/handbook/eda/section3/autocopl.htm

libra_py.acf.acf_vec(data, dt, opt=0)[source]

Compute the autocorrelation function of the given data set

Parameters
  • data (list of VECTOR objects) – sequence of real-valued 3-dimensional vectors

  • dt (double) – time distance between the adjacent data points [units: general]

  • opt (int) –

    selector of the convention to to compute ACF

    • 0 : the chemist convention, (1/(N-h)) Sum_{t=1,N-h} (Y[t]*Y[t+h])

    • 1 : the statistician convention, (1/N) Sum_{t=1,N-h} (Y[t]*Y[t+h])

Returns

(T, nautocorr, autocorr), where:

T (list of sz doubles ): lag time scale for the ACF [units: same as for dt] nautocorr (list of sz doubles ): normalized ACF autocorr (list of sz doubles ): un-normalized ACF

Return type

tuple

SeeAlso:

https://www.itl.nist.gov/div898/handbook/eda/section3/autocopl.htm