pyacs.lib.astrotime.day_since_decyear

Calculate the number of days since a reference decimal year.

pyacs.lib.astrotime.day_since_decyear.day_since_decyear(decyear, ref_decyear)[source]

Calculate the number of days since a reference decimal year.

Parameters:

decyear (float or array-like) – Decimal year(s).
ref_decyear (float) – Reference decimal year.

Returns:

Days elapsed. Negative means before reference date. Useful for postseismic analysis.

Return type:

float or ndarray

Examples

>>> import pyacs
>>> ref_decyear=pyacs.cal2decyear(16,4,2016,ut=pyacs.hmsmicros2ut(23, 58, 33))
>>> pyacs.day_since_decyear(pyacs.cal2decyear(17,4,2016,ut=pyacs.hmsmicros2ut(23, 58, 32)),ref_decyear)
>>> 0.9999884259232203
>>> pyacs.day_since_decyear(pyacs.cal2decyear(17,4,2016,ut=pyacs.hmsmicros2ut(23, 58, 33)),ref_decyear)
>>> 0.9999999999854481
>>> pyacs.day_since_decyear(pyacs.cal2decyear(16,4,2017,ut=pyacs.hmsmicros2ut(23, 58, 33)),ref_decyear)
>>> 364.9999999999345
>>> ld=pyacs.mjd2decyear(np.arange(pyacs.cal2mjd(13,4,2016),pyacs.cal2mjd(19,4,2016)))
>>> pyacs.day_since_decyear(ld,ref_decyear)
>>> array([-3.499, -2.499, -1.499, -0.499,  0.501,  1.501])