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A 1-D file-based point-source fitting model.
PTSRC1D is a file-based model that may be used
in fitting sources, to determine, e.g., if they are point-like
or extended.
This model cannot be used as an instrument model.
ASCII and FITS formats are allowed for the input model file
. The current implementation requires that the bin size of the
data and the PTSRC1D model file are the same. The
number of bins can be different.
The model has several parameters, which can be used to adjust the
model array to be used in fitting.
"xsize" parameter defines the number of bins extracted from the
file to be used in the model.
xoff = 0 parameters defines the center of the array and
it should be left at 0 in CIAO 3.2 version of the model.
"norm" parameter is thawed by definition and it is defined
as a total number of counts (values) in the model. The best-fit
value for a point-like source will be approximately equal to the
number of detected counts from the source.
"xpos" parameter indicates where the center of the
sub-array is located in the extracted model array, for example it
should be set to the location of the source centroid if the input file
is a gaussian function. Note that the initial value of the
xpos is estimated using the input dataset.
PTSRC1D Parameters
| 1 | file | input file name (FITS or ASCII) |
| 2 | xsize | x-full-width of the subset region of the model file |
| 3 | xoff | x-direction offset |
| 4 | xpos | x-position of the centroid in the data coordinates |
| 5 | norm | normalization |
The example below shows the initial parameter values for the
PTSRC1D model. Note that the default xsize
value is set to 32 before the data file is read in. After reading the
data file the xsize is set to the size of the array in
the model file.
sherpa> ptsrc1d[p1]
sherpa> show p1
ptsrc1d[p1] (integrate: on)
Param Type Value Min Max Units
----- ---- ----- --- --- -----
1 file string: "none"
2 xsize frozen 32 1 1024
3 xoff frozen 0 -512 512
4 xpos thawed 12.5 12.5 197.5
5 norm thawed 1 0 1000
shrpa> p1.file="model.dat"
sherpa> show p1
ptsrc1d[p1] (integrate: on)
Param Type Value Min Max Units
----- ---- ----- --- --- -----
1 file string: "model.dat"
2 xsize frozen 38 1 38
3 xoff frozen 0 -19 19
4 xpos thawed 12.5 12.5 197.5
5 norm thawed 1 0 1000
sherpa> source 1 = p1
sherpa> fit
- sherpa
-
atten,
bbody,
bbodyfreq,
beta1d,
beta2d,
box1d,
box2d,
bpl1d,
const1d,
const2d,
cos,
delta1d,
delta2d,
dered,
devaucouleurs,
edge,
erf,
erfc,
farf,
farf2d,
fpsf,
fpsf1d,
frmf,
gauss1d,
gauss2d,
gridmodel,
hubble,
jdpileup,
linebroad,
lorentz1d,
lorentz2d,
models,
nbeta,
ngauss1d,
poisson,
polynom1d,
polynom2d,
powlaw1d,
ptsrc2d,
rsp,
rsp2d,
schechter,
shexp,
shexp10,
shlog10,
shloge,
sin,
sqrt,
stephi1d,
steplo1d,
tan,
tpsf,
tpsf1d,
usermodel,
xs,
xsabsori,
xsacisabs,
xsapec,
xsbapec,
xsbbody,
xsbbodyrad,
xsbexrav,
xsbexriv,
xsbknpower,
xsbmc,
xsbremss,
xsbvapec,
xsc6mekl,
xsc6pmekl,
xsc6pvmkl,
xsc6vmekl,
xscabs,
xscemekl,
xscevmkl,
xscflow,
xscompbb,
xscompls,
xscompst,
xscomptt,
xsconstant,
xscutoffpl,
xscyclabs,
xsdisk,
xsdiskbb,
xsdiskline,
xsdiskm,
xsdisko,
xsdiskpn,
xsdust,
xsedge,
xsequil,
xsexpabs,
xsexpdec,
xsexpfac,
xsgabs,
xsgaussian,
xsgnei,
xsgrad,
xsgrbm,
xshighecut,
xshrefl,
xslaor,
xslorentz,
xsmeka,
xsmekal,
xsmkcflow,
xsnei,
xsnotch,
xsnpshock,
xsnsa,
xsnteea,
xspcfabs,
xspegpwrlw,
xspexrav,
xspexriv,
xsphabs,
xsplabs,
xsplcabs,
xsposm,
xspowerlaw,
xspshock,
xspwab,
xsraymond,
xsredden,
xsredge,
xsrefsch,
xssedov,
xssmedge,
xsspline,
xssrcut,
xssresc,
xssssice,
xsstep,
xstbabs,
xstbgrain,
xstbvarabs,
xsuvred,
xsvapec,
xsvarabs,
xsvbremss,
xsvequil,
xsvgnei,
xsvmcflow,
xsvmeka,
xsvmekal,
xsvnei,
xsvnpshock,
xsvphabs,
xsvpshock,
xsvraymond,
xsvsedov,
xswabs,
xswndabs,
xsxion,
xszbbody,
xszbremss,
xszedge,
xszgauss,
xszhighect,
xszpcfabs,
xszphabs,
xszpowerlw,
xsztbabs,
xszvarabs,
xszvfeabs,
xszvphabs,
xszwabs,
xszwndabs
- slang
-
usermodel
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