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The results of the minimization are printed to the standard output and written to the files in the `output/` directory (name of the directory can be changed in the steering.txt). The quality of the fit can be judged based on total $`\chi^2`$ per degrees of freedom. It is printed for each iteration as
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The resulting $`\chi^2`$ is reported for each data set and for correlated systematic uncertainties separately. This information is printed and written to the `output/Results.txt` file. The `Results.txt` file contains additional information about shifts of the correlated systematic uncertainties.
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The minimization information from minuit is stored in the `output/minuit.out.txt` file. The verboseness level of this information can be changed by minuit commands in the `parameters.yaml` file. Make sure that the minuit does not report errors or warnings at the end of minimisation.
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Point by point comparison of the data and predictions after the minimization is provided in `output/fittedresults.txt` file. The file reports three columns corresponding to three first bins of the input tables, data value, sum in quadrature of statistical and uncorrelated systematic uncertainty, total uncertainty, the predicted value, after applying correlated systematic shifts, pulls between data and theory calculated as (data-theory)/uncorrelated_error, data set index. Similar information is stored in `pulls.first.txt` and `pulls.last.txt` ( dataset index, first bin, second bin, third bin, data, theory, pull), however theory is not adjusted for systematic error shifts in this case.
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The output PDFs are stored in forms of tables in `output/pdfs_q2val_XX.txt` files. Each of the files reports values of gluon and quark PDFs as a function of $`x`$ for fixed $`Q^2`$ points. The $`Q^2`$ values and $`x`$ grid are specified by &Output namelist in the `steering.txt`
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The PDF information and data to theory comparisons can be plotted using the `bin/xfitter-draw` program. The program requires the fit output directory as an argument. Calling the program with more directories as arguments provides comparison of the PDFs obtained in the various fits. For a full list of the available options of xfitter-draw please type:
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```
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bin/xfitter-draw --help
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```
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Finally, the xFitter package provides PDFs in [LHAPDF format](WriteLHAPDF6) |
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\ No newline at end of file |
