Akima spline interpolation function.


akima(old_x, old_y, new_x)


The x vector of the curve to be interpolated.
The y vector of the curve to be interpolated.
A vector containing x values for which new y values are to be calculated.


Templex Expression Result
{akima({0,3,5,8}, 2.68861, 3.74086, 5,
{2,5,9,7} ,1:5:1)} 6.89752, 9
Curve Math Vectors Result
x = new_x

y = akima(c1.x, c1.y, x)

Given c1, a curve is created with interpolated y values at each point of new_x.


The Akima spline function estimates a y-value for each element in new_x such that the new points lie on or near the curve defined by old_x, old_y. old_x and new_x must be strictly increasing. The resulting vector contains a y-value estimate for each element in new_x.

The Akima spline function performs interpolation only. All values of new_x must fall between the minimum of old_x and the maximum of old_x. The new values are obtained using the Akima spline interpolation method.

For the ECS derivation of the Akima method, see the Journal of the Association for Computing Machinery, Vol. 17, No. 4, October 1970, pp. 589-602.