The result, shown in Fig.
\ref{411091}, indicates that the fractional error in the fit is less than ± 0.2% over most of the temperature range, but starts to break down at the low temperature end. To formally evaluate the goodness of fit, we would need to know the precision of the resistance measurements for each data point. The precision of the data points can be taken into account during the Chebyshev fitting process by
specifying the appropriate weights in
Chebyshev.fit
.