- Joined
- 12/6/18
- Messages
- 26
- Points
- 13
SmoothStep is monotonous and positive but its convexity changes midway between knots.
SmoothStep is well suited to risk views because it is local and interpolates a bell-shaped bump as Jherek mentioned. But I would not recommend it for the construction of the underlying yield curve, especially with a sparse set of instruments.
Cubic spline is less suited to risks because it spills out of the bracketing knots unless modified but it may be more suitable for the construction of curves. A higher order scheme as suggested by Jherek may yield even better results.
The risk view allows to dissociate construction from risk and select the more appropriate scheme for each task. For risks, a well localized scheme works best: piecewise constant, linear or smoothstep depending on differentiation requirements. Construction is a different story.
SmoothStep is well suited to risk views because it is local and interpolates a bell-shaped bump as Jherek mentioned. But I would not recommend it for the construction of the underlying yield curve, especially with a sparse set of instruments.
Cubic spline is less suited to risks because it spills out of the bracketing knots unless modified but it may be more suitable for the construction of curves. A higher order scheme as suggested by Jherek may yield even better results.
The risk view allows to dissociate construction from risk and select the more appropriate scheme for each task. For risks, a well localized scheme works best: piecewise constant, linear or smoothstep depending on differentiation requirements. Construction is a different story.
Last edited: