ECBYieldCurve           Yield curve data spot rate, AAA-rated bonds,
                        maturities from 3 months to 30 years
FedYieldCurve           Federal Reserve interest rates
NSrates                 Interest rates of the Nelson-Siegel's model.
Nelson.Siegel           Estimation of the Nelson-Siegel parameters
Srates                  Interest rates of the Svensson's model.
Svensson                Estimation of the Svensson parameters
YieldCurve-package      Modelling and estimation of the yield curve
