How to convert matlab function 'pchip' to c code with matlab coder

问题

I have a problem with Matlab Coder. I would like to generate C code from Matlab interpolating function pchip. I verified the function with coder.screener and it says it's available for code generation but when I try to build pchip.m file I get this error:

The function 'pchip' is not supported for standalone code generation. See the documentation for coder.extrinsic to learn how you can use this function in simulation.

Can anyone help me? I really need to convert this function in C for a program I am writing.

回答1:

Limitations of pp = pchip(x,y) for code generation from the documentation:

• Input x must be strictly increasing.
• Does not remove y entries with NaN values.
• If you generate code for the pp = pchip(x,y) syntax, you cannot input pp to the ppval function in MATLAB. To create a MATLAB pp structure from a pp structure created by the code generation software:
  • In code generation, use unmkpp to return the piecewise polynomial details to MATLAB.
  • In MATLAB, use mkpp to create the pp structure.

So, please check that you fulfill the previous points; especially the last one. You have examples in the documentation of how to make/unmake a picewise polynomial.

来源：https://stackoverflow.com/questions/23229744/how-to-convert-matlab-function-pchip-to-c-code-with-matlab-coder