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data:line_fitting_idl [2024/11/12 17:51] Peter Young [Fitting a Gaussian at each spatial pixel in a raster (IDL)] |
data:line_fitting_idl [2024/11/12 18:02] (current) Peter Young [IDL Software for Emission Line Fitting] |
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| ====== IDL Software for Emission Line Fitting ====== | ====== IDL Software for Emission Line Fitting ====== | ||
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| ===== Fitting a Gaussian at each spatial pixel in a raster ===== | ===== Fitting a Gaussian at each spatial pixel in a raster ===== | ||
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| If you have problems running the EIS software on SPICE data, please contact [[https://science.gsfc.nasa.gov/sed/bio/peter.r.young|Dr. Peter Young]]. | If you have problems running the EIS software on SPICE data, please contact [[https://science.gsfc.nasa.gov/sed/bio/peter.r.young|Dr. Peter Young]]. | ||
| - | ===== Fitting a Gaussian to a spatially-averaged spectrum (IDL) ===== | + | ===== Fitting a Gaussian to a spatially-averaged spectrum ===== |
| In this scenario, a spatial region is selected in the raster, perhaps a bright point or a loop, and the spectra are averaged over this region to produce a single, 1D spectrum. Gaussians are then fit to this spectrum. The procedure is as follows: | In this scenario, a spatial region is selected in the raster, perhaps a bright point or a loop, and the spectra are averaged over this region to produce a single, 1D spectrum. Gaussians are then fit to this spectrum. The procedure is as follows: | ||
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| These routines are modified from routines originally written for Hinode/EIS. Further details can be found in [[https://doi.org/10.5281/zenodo.6339584 | These routines are modified from routines originally written for Hinode/EIS. Further details can be found in [[https://doi.org/10.5281/zenodo.6339584 | ||
| |EIS Software Note 15]]. | |EIS Software Note 15]]. | ||
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| + | ===== Using an auto_fit template for mask spectra ===== | ||
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| + | The fitting templates created for eis\_auto\_fit can be useful for fitting mask spectra as well. First create the template for the window you are interested in: | ||
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| + | '' | ||
| + | IDL> wd=spice\_getwindata(file)\\ | ||
| + | IDL> eis\_fit\_template,wd,template \\ | ||
| + | '' | ||
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| + | Now create the mask spectrum using the procedure described above. You can then apply the template to the mask spectrum by doing: | ||
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| + | '' | ||
| + | IDL> fit=spice\_mask\_auto\_fit(wd,spec,template,chi2=chi2) | ||
| + | '' | ||
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| + | The output structure ''fit'' contains the fit results. The reduced chi-square value for the fit is returned in the optional output. To overplot the fit on the spectrum, do: | ||
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| + | '' | ||
| + | IDL> p=spice\_plot\_mask\_auto\_fit(spec,fit) | ||
| + | '' | ||
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