"""
Calculate the number of days since a reference decimal year.
"""
[docs]
def day_since_decyear(decyear,ref_decyear):
"""
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
-------
float or ndarray
Days elapsed. Negative means before reference date. Useful for
postseismic analysis.
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])
"""
from .decyear2mjd import decyear2mjd
mjd=decyear2mjd(decyear)
ref_mjd=decyear2mjd(ref_decyear)
return mjd-ref_mjd