See for example [1] for a discussion of interpolation in finance. See also our QuantLib calculator for curve interpolation here http://quantpanel.bnikolic.co.uk/InterpolatedCurve.
The following interpolation types are available in the QuantLib add-in:
BackwardFlat
ForwardFlat
Linear
LogLinear
CubicNaturalSpline
LogCubicNaturalSpline
MonotonicCubicNaturalSpline
KrugerCubic
FritschButlandCubic
Parabolic
LogParabolic
MonotonicParabolic
MonotonicLogParabolic
Abcd
An interpolation can be constructed by calling the qlInterpolation
function and then used by calling the qlInterpolationInterpolate
function.
Below is an example plot of 10 data points interpolated using the various types of interpolation:
The QuantLib add-in provides two types of two dimensional interpolation:
BiLinear
BiCubic
Two dimensional interpolation objects are created using the
qlInterpolation2D
function and can then be used to calculate an
estimated value by using the qlInterpolation2DInterpolate
function.