Simulink/MATLAB error in akima interpolation

Good morning everyone,

I was trying to runi the simulink block in the picture, but it gives the following error and i do not understant why.

alpha is fed through a ramp that goes from 0 to 180.

Furthermore, if i use the pchip function, which has the exactly same structure of makima function, it gives me no errors.

Answer 1

[Salman Ahmed]

Hi Marco,

In a MATLAB Function block, you can only use the subset of the MATLAB language and language features that are supported for C/C++ code generation. However, you can define the function using coder.extrinsic in case the function is not supported for code generation. Since extrinsic functions execute in the workspace during model simulation, your error will be resolved. Try adding the following to your MATLAB Fcn block

coder.extrinsic('makima');

You may also consider preallocating some memory to Fx1 using coder.nullcopy. Try adding this line also, if you face any errors.

Fx1 = coder.nullcopy(zeros(s)); % replace s with the expected size of Fx1