Utility Bugs: dcounts

Bugs

1. Problems calculating flux and counts over a range.

2. Working in counts/channel space

Bugs

1. Problems calculating flux and counts over a range.

   The behavior described in this bug applies to the following commands:

   • [B]EFLUX,
   • [B]PFLUX,
   • [B]DCOUNTS,
   • [B]MCOUNTS,
   • and the corresponding "get" commands (e.g. get_eflux).

   Given x > 0:

   1. "EFLUX (0:x)" returns the same value as "EFLUX" (i.e. the flux over the full range of the dataset), when it should return the flux integrated from the start of the dataset to x.
   2. "EFLUX (x:0)" returns the same value as "EFLUX (x)." This should return an error since x > 0, so the range isn't sensible.

   Workaround:

   replace 0 with a small decimal, e.g. 0.001. Then case 1 gives the correct answer (flux from the start of the dataset to x), and case 2 gives 0 (which at least tells you that you did something wrong).

2. Working in counts/channel space

   dcounts force you to work in either energy or wavelength space, even if analysis channel has been issued.

   Workaround:

   temporarily unset the instrument model. For example, if you have a PHA file, an RMF, and an ARF such as:

   sherpa> data foo.pha
   sherpa> instrument = rsp[rr](foo.rmf,foo.arf)
   

   then you can do (note that the first command ends at the "="):

   sherpa> instrument = 
   sherpa> analysis channels
   sherpa> dcounts (22:70)
   sherpa> instrument = rr
   sherpa> analysis energy
   

   to get the counts in a range of channels.