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Last modified: 21 September 2006

URL: http://cxc.harvard.edu/sherpa3.4/bugs/pl_general.html
Hardcopy (PDF): A4 | Letter

Plotting Bugs: general


Bugs

  1. When plotting scatter data (i.e., multiple y-values per x-value), x-errorbars are not plotted, even when the user requests x-errorbars.

  2. One cannot plot convolved model components, only the overall convolved model stack.

  3. Displayed x-errorbars are only correct if data are evenly binned.


Bugs

  1. When plotting scatter data (i.e., multiple y-values per x-value), x-errorbars are not plotted, even when the user requests x-errorbars.

  2. One cannot plot convolved model components, only the overall convolved model stack.

    sherpa> source = gauss[g]+pow[p]
    sherpa> lp source      # fine (unconvolved stack, g+p)
    sherpa> lp model       # fine (convolved stack, g+p)
    sherpa> lp g           # fine (_unconvolved_ component p)
    

    Workaround:

    sherpa> source = g
    sherpa> lp model
    sherpa> source = p
    sherpa> lp model
    

    If one wishes to overplot convolved components with the convolved stack (XSPEC-style counts plotting), it can be done via a Sherpa/S-Lang module workaround:

    sherpa> source = g
    sherpa> cong = get_mcounts()   # array of g amplitudes, convolved 
    sherpa> source = p
    sherpa> conp = get_mcounts()   # array of p amplitudes, convolved 
    sherpa> source = p+g
    sherpa> cons = get_mcounts()   # array of p+g amplitudes, convolved 
    sherpa> conx = get_axes()
    sherpa> print(conx)
    axistype         =  Energy
    axisunits        =  keV
    lo               =  Float_Type[95]
    hi               =  Float_Type[95]
    mid              =  NULL
    sherpa> mid = (conx.lo+conx.hi)/2.0  # make array of bin midpoints
    sherpa> () = curve(mid,cons)   # plot in ChIPS
    sherpa> () = curve(mid,conp)
    sherpa> () = curve(mid,cong)
    
  3. Displayed x-errorbars are only correct if data are evenly binned.

Hardcopy (PDF): A4 | Letter
Last modified: 21 September 2006


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