Fits a discount function to the exponential form
$$
d(t) = \sum_{i=1}^9 c_i \exp^{-kappa i t}
$$
where the constants $ c_i $ and $ \kappa $ are to be
determined. See:Li, B., E. DeWetering, G. Lucas, R. Brenner
and A. Shapiro (2001): "Merrill Lynch Exponential Spline
Model." Merrill Lynch Working Paper
Exponential-splines fitting method
Fits a discount function to the exponential form $$ d(t) = \sum_{i=1}^9 c_i \exp^{-kappa i t} $$ where the constants $ c_i $ and $ \kappa $ are to be determined. See:Li, B., E. DeWetering, G. Lucas, R. Brenner and A. Shapiro (2001): "Merrill Lynch Exponential Spline Model." Merrill Lynch Working Paper
warning convergence may be slow