Akima interpolation algorithm

Question

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Akima interpolation of an array of doubles

I'm searching for an algorithm for Akima interpolation, but I can't find one after googling for a while. I write my application in Objective-C, but the programming language doesn't matter.

It would be very kind if you can provide any code or links. Thanks

Answer 1

edit:

see this SO answer for an updated version of the list below.

original answer:

Akima's original paper

http://student.ndhu.edu.tw/~u9111023/akima.pdf

C# implementation

https://github.com/mathnet/mathnet-numerics/blob/master/src/Numerics/Interpolation/Algorithms/AkimaSplineInterpolation.cs

C++ implementation

http://www.koders.com/cpp/fid1393B9D668316C1700966643DE0609660B9CB13A.aspx?s=%22Brian+Smith%22

C implementation

http://packages.debian.org/source/squeeze/spline

Akima's Fortran implementation

http://cran.r-project.org/web/packages/akima/

Fortran 90 implementation

http://miyoshi.googlecode.com/svn-history/r72/trunk/common/common.f90

Lisp implementation "for AutoCAD 2d-Polylines"

http://autocad.xarch.at/code/candido/akima.lsp

Matlab implementation

http://www.mathworks.se/matlabcentral/fileexchange/1814-akima-interpolation

Python implementation

http://www.lfd.uci.edu/~gohlke/code/akima.py.html