coder.extr​insic('app​lycform'); not support for code generation ? how to use instead of applycform

coder.extrinsic('applycform'); not support for code generation ?

Answer 1

[Walter Roberson]

You are misusing coder.extrinsic

https://www.mathworks.com/help/simulink/slref/coder.extrinsic.html

"coder.extrinsic declares extrinsic functions. During simulation, the code generator produces code for the call to an extrinsic function, but does not produce the function's internal code. Therefore, simulation can run only on platforms where MATLAB software is installed. During standalone code generation, MATLAB attempts to determine whether the extrinsic function affects the output of the function in which it is called — for example by returning mxArrays to an output variable. Provided that there is no change to the output, MATLAB proceeds with code generation, but excludes the extrinsic function from the generated code. Otherwise, compilation errors occur."

You can use something like https://www.mathworks.com/help/simulink/slref/coder.ceval.html

if isdeployed()
  transformed_cform = coder.ceval('my_applycform', cform_to_transform)
else
  transformed_cform = applycform(cform_to_transform);
end

where my_applycform is C code you have written to replace applycform . This would not be code generated by MATLAB: this would be work-alike code that you wrote yourself.

For emphasis: there is no way to get MATLAB to generate code for applycform, so you need to write replacement code. (Or you could apply for a job at Mathworks to work through all of the steps needed on the Mathworks side to be able to generate code for applycform.)

[Sina Alighanbari]

Hi, I have a question about coder.extrinsic. I am using MATLAB R2013b for a special purpose. The solver that I am using used to work with this version of MATLAB but currently it is not working and I got this error:

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

Although my simulink and codes are working with R2015b and R2017a (and even with R2013b in the past)without any problem. Does anyone have any idea?

[Walter Roberson]

That routine does not appear to be supplied by Mathworks. It is possibly from https://archive.siam.org/books/kelley/fr16/matlabcode.php

[Sina Alighanbari]

Thanks for your reply. I have another question. If we use matlab R2017a and generate C code for a matlab file, is it possible to use that C code in matlab R2013b with coder.ceval instead of the original matlab file?

[Walter Roberson]

Probably. There is a risk that the r2017a generated code might be targeted to a later release of C than was supported in R2013b, but I think you can control the target language version.