- sherpa.astro.ui.set_exposure(id, exptime=None, bkg_id=None)¶
Change the exposure time of a PHA data set.
The exposure time of a PHA data set is taken from the
EXPOSUREkeyword in its header, but it can be changed once the file has been loaded.
exptime (num) – The exposure time, in seconds.
The function does not follow the normal Python standards for parameter use, since it is designed for easy interactive use. When called with a single un-named argument, it is taken to be the
exptimeparameter. If given two un-named arguments, then they are interpreted as the
exptimeparameters, respectively. The remaining parameters are expected to be given as named arguments.
Increase the exposure time of the default data set by 5 per cent.
>>> etime = get_exposure() >>> set_exposure(etime * 1.05)
Use the EXPOSURE value from the ARF, rather than the value from the PHA file, for data set 2:
>>> set_exposure(2, get_arf(2).exposure)
Set the exposure time of the second background component of the ‘jet’ data set.
>>> set_exposure('jet', 12324.45, bkg_id=2)