Examples

   > imsim sim model=mymod
   Using model quality array...
   Model is exposure corrected, scaling up by exposure of 23212.4 seconds
   Normalising model...
   Model contains 16266.1 counts
   BACK - Background counts /!/ > 16266
   SOURCEC - Number of counts per source /!/ > 100
   SOURCEP - Source positions /[0,0]/ > 2,-4
   WIDTHS - Width of gaussian for psf convolution /0/ >
   SRADIUS - Half width of psf in pixels /15/ >
   ...
   PSF - Choose PSF for simulated sources /'ANALYTIC'/ > XRT_PSPC
   MASK - PSPC psf option (LIST for descriptions) /'VARPROFILE'/ >
   Loaded XRT psf cube with 10 energy channels
   AUX - Mean photon energy in KeV > 0.6
   Background 8051 counts
   Source 1 95 counts
  

   > imsim nfile=5 out=sim model=mymod
   ...
   as before
   ...
   LOGNS - Choose source counts using Log NS /NO/ > y
   SNORM - Normalisation flux > 400
   NSNORM - Number of sources with flux >= SNORM/degree**2 > 10
   ED - Index of Log NS for flux 1.5
   EU - Index of Log NS for flux>SB > 1.2