The cardinal cubic Hermite interpolator is similar to the cubic Hermite interpolator but optimised for equispaced data.
Performance:
This allows for constant-time evaluation.
Usage
cardinal_cubic_hermite(y, dydx, x0, dx)
Arguments
- y
Numeric vector of ordinates (y-coordinates).
- dydx
Numeric vector of derivatives (slopes) at each point.
- x0
Numeric value of the first abscissa (x-coordinate).
- dx
Numeric value of the spacing between abscissas.
Value
An object of class cardinal_cubic_hermite with methods:
interpolate(xi): Evaluate the interpolator at point xi.
prime(xi): Evaluate the derivative of the interpolator at point xi.
domain(): Get the domain of the interpolator.
Examples
y <- c(0, 1, 0)
dydx <- c(1, 0, -1)
interpolator <- cardinal_cubic_hermite(y, dydx, 0, 1)
xi <- 0.5
interpolator$interpolate(xi)
#> [1] 0.625
interpolator$prime(xi)
#> [1] 1.25
interpolator$domain()
#> [1] 0 2