akimaInterp(x, y, xi)
xi
as a vector.Hyman, J. (1983). Accurate Monotonicity Preserving Cubic Interpolation. SIAM J. Sci. Stat. Comput., Vol. 4(4), pp. 645-654.
Akima, H. (1996). Algorithm 760: Rectangular-Grid-Data Surface Fitting that Has the Accurancy of a Bicubic Polynomial. ACM TOMS Vol. 22(3), pp. 357-361.
Akima, H. (1996). Algorithm 761: Scattered-Data Surface Fitting that Has the Accuracy of a Cubic Polynomial. ACM TOMS, Vol. 22(3), pp. 362-371.
kriging
, akima::aspline
, akima::interp
x <- c( 0, 2, 3, 5, 6, 8, 9, 11, 12, 14, 15)
y <- c(10, 10, 10, 10, 10, 10, 10.5, 15, 50, 60, 85)
xs <- seq(12, 14, 0.5) # 12.0 12.5 13.0 13.5 14.0
ys <- akimaInterp(x, y, xs) # 50.0 54.57405 54.84360 55.19135 60.0
xs; ys
plot(x, y, col="blue", main = "Akima Interpolation")
xi <- linspace(0,15,51)
yi <- akimaInterp(x, y, xi)
lines(xi, yi, col = "darkred")
grid()
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