Module calc

splitpy.calc.split_SilverChan(trQ, trT, baz, t1, t2, maxdt, ddt, dphi)

Calculates splitting based on the minimization of energy on the corrected transverse component (Silver and Chan, 1990)

Parameters
  • trQ (Trace) – Radial component seismogram

  • trT (Trace) – Tangential component seismogram

  • baz (float) – Back-azimuth - pointing to earthquake from station (degrees)

  • t1 (UTCDateTime) – Start time of picking window

  • t2 (UTCDateTime) – End time of picking window

Returns

  • Ematrix (ndarray) – Matrix of T component energy

  • trQ_c (Trace) – Trace of corrected radial component of motion

  • trT_c (Trace) – Trace of corrected tangential component of motion

  • trFast (Trace) – Trace of corrected fast direction of motion

  • trSlow (Trace) – Trace of corrected slow direction of motion phiSC : float Azimuth of fast axis (deg)

  • dttSC (foat) – Delay time between fast and slow axes (sec)

  • phi_min (float) – Azimuth used in plotting routine

splitpy.calc.split_RotCorr(trQ, trT, baz, t1, t2, maxdt, ddt, dphi)

Calculates splitting based on the maximum correlation between corrected radial and tangential components of motion

Parameters
  • trQ (Trace) – Radial component seismogram

  • trT (Trace) – Tangential component seismogram

  • baz (float) – Back-azimuth - pointing to earthquake from station (degrees)

  • t1 (UTCDateTime) – Start time of picking window

  • t2 (UTCDateTime) – End time of picking window

Returns

  • Ematrix (ndarray) – Matrix of T component energy

  • trQ_c (Trace) – Trace of corrected radial component of motion

  • trT_c (Trace) – Trace of corrected tangential component of motion

  • trFast (Trace) – Trace of corrected fast direction of motion

  • trSlow (Trace) – Trace of corrected slow direction of motion phiSC : float Azimuth of fast axis (deg)

  • dttSC (foat) – Delay time between fast and slow axes (sec)

  • phi_min (float) – Azimuth used in plotting routine

splitpy.calc.tshift(trace, tt)

Shifts a Trace object

Parameters
  • trace (Trace) – Seismogram to apply shift

  • tt (float) – Lag time for shifting

Returns

rtrace – Shifted version of trace

Return type

Trace

splitpy.calc.split_dof(tr)

Determines the degrees of freedom to calculate the confidence region of the misfit function

Parameters

tr (Trace) – Seismogram

Returns

  • dof (float) – Degrees of freedom

  • From Walsh, JGR, 2013

splitpy.calc.split_errorSC(tr, t1, t2, q, Emat, maxdt, ddt, dphi)

Calculate error bars based on a F-test and a given confidence interval q

Parameters
  • tr (Trace) – Seismogram

  • t1 (UTCDateTime) – Start time of picking window

  • t2 (UTCDateTime) – End time of picking window

  • q (float) – Confidence level

  • Emat (ndarray) – Energy minimization matrix

Returns

  • err_dtt (float) – Error in dt estimate (sec)

  • err_phi (float) – Error in phi estimate (degrees)

  • err_contour (ndarray) – Error contour for plotting

splitpy.calc.split_errorRC(tr, t1, t2, q, Emat, maxdt, ddt, dphi)

Calculates error bars based on a F-test and a given confidence interval q.

Note

This version uses a Fisher transformation for correlation-type misfit.

Parameters
  • tr (Trace) – Seismogram

  • t1 (UTCDateTime) – Start time of picking window

  • t2 (UTCDateTime) – End time of picking window

  • q (float) – Confidence level

  • Emat (ndarray) – Energy minimization matrix

Returns

  • err_dtt (float) – Error in dt estimate (sec)

  • err_phi (float) – Error in phi estimate (degrees)

  • err_contour (ndarray) – Error contour for plotting