Differences between interpolations and approximation

Red – Input data
Green – Hermite interpolation
Purple – Akima interpolation
Blue – Cubic Spline interpolation
Turquoise – Cubic B-Spline approximation

Examples to show basic differences between approximation and interpolation.

Turquoise – Approximation - Cubic B-Spline passing between node points

Green, Blue, Purple curves are interpolations:

• Blue – Cubic Spline the best interpolation giving the user the smoothest shape
• Green – Hermite is compromise between sharp Akima and smooth Cubic Spline
• Purple – Akima gives a sharper interpolation compared with Cubic Spline and Hermite