Diagrams.CubicSpline

A cubic spline is a smooth, connected sequence of cubic curves passing through a given sequence of points. This module provides the cubicSpline method, which can be used to create closed or open cubic splines from a list of points. For access to the internals of the spline generation algorithm (including in particular a solver for cyclic tridiagonal systems of linear equations), see Diagrams.CubicSpline.Internal.

Constructing paths from cubic splines

cubicSpline :: (V t ~ v, N t ~ n, TrailLike t, Fractional (v n)) => Bool -> [Point v n] -> t

Construct a spline path-like thing of cubic segments from a list of vertices, with the first vertex as the starting point. The first argument specifies whether the path should be closed.

pts = map p2 [(0,0), (2,3), (5,-2), (-4,1), (0,3)]
spot = circle 0.2 # fc blue # lw none
mkPath closed = position (zip pts (repeat spot))
             <> cubicSpline closed pts
cubicSplineEx = (mkPath False ||| strutX 2 ||| mkPath True)
              # centerXY # pad 1.1

For more information, see http://mathworld.wolfram.com/CubicSpline.html.