The fit files here are used to smooth the experimental R-data. This
smoothing is necessary for calculating the principal value integrals
in the time-like region. Fit ranges are chosen to avoid resonances and
to ensure smooth transitions between ranges. The fit functions are
Chebyshev polynomials applied to energy intervals. Their coefficients
are stored in include files like epemfit0814new.h, which is used by
Rdat_fit.f for the 0.8 to 1.4 GeV range. The fitting procedures in
fitRdata_gnu.sh handle the R-data compilation from Rdat_all.f. The new
fit is shown together with the old fit from Rdat_fit.f and can be
accepted for update if it improves substantially. The updated fit is
copied to the main directory using a *.hx extension to prevent
unwanted overwriting. To activate the new version, move it from *.hx
to *.h and recompile:

cd ..
mv epemfit0814new.hx epemfit0814new.h
make

Then the new fit is active. Updating the fit is only necessary if the
R-data has changed or been improved. If there is no update to the
R-data, the fit routines are used solely to examine or verify the
smoothed representation of the existing R-data without making changes.

The same procedure applies to the other channels R3Gdat, R33dat, RN2dat
and RGGdat (the latter is a cross-check for Rdat only)
