a la Diebold,Rudebusch,Aruoba(2006) in one step with Kalman filter.
DNS-baseline: Dynamic Nelson-Siegel
DNSS-baseline: Dynamic Nelson-Siegel-Svensson
werleycordeiro/Kalman-Filter-Dynamic-Nelson-Siegel-and-Svensson
Dynamic Nelson-Siegel and Svensson in one step
R