_fit_xput_lite#
- irispy.utils.response._fit_xput_lite(observation_time, time_cal_coeffs, cal_coeffs)[source]#
To calculate the coefficients of best-fit time function for throughput, for which we apply a fit based on
cal_coeffs.The procedure involved in this function is as follows:
The time difference (in years) is computed from the
observation_timeandtime_cal_coeffs.A least-squares fit is performed to determine the best fit for the time-dependent effective areas given the time difference.
Goal is to replicate the base functionality of the IDL routine
fit_iris_xput.proin the SSWIDL package but without the optional keyword argument.- Parameters:
observation_time (
astropy.time.Time) – Observation time.time_cal_coeffs (
astropy.time.Time) – Start and end times of intervals of constantcal_coeffs[i]. These should be in “utime” format.cal_coeffs (
numpy.ndarray) – Coefficients of best-fit function, with at least two columns.
- Returns:
Yields the fit used to compute the effective area using the input times
observation_time.- Return type: