Why aren't some functions supported for code generation with MATLAB Coder?

I'm trying to use the MATLAB Coder to generate C code from my MATLAB scripts and am seeing an error of the form

Function "<name>" is not supported for code generation

regarding certain built-in MATLAB functions. What does this error mean, and why isn't code generation supported for these functions?

Answer 1

[MathWorks Support Team]

Some MATLAB functions are not supported for code generation. If you have would like to know whether a function you are using is supported for code generation, please check this complete list of the Functions and Objects Supported for C/C++ Code Generation in the latest release. 

Generally speaking, there is no common component of the unsupported functions that causes them to be unsupported by MATLAB Coder. If you are interested in enabling code generation for a specific built-in function, you can use the web form to Request Code Generation Support for MATLAB Functions.

The following workarounds can be used when generating code for MATLAB code that uses unsupported functions:

1. The

coder.ceval

function will allow you to call an external C or C++ function. This option will require you to either write your own C/C++ code or find an existing C/C++ function that accomplishes the task of the unsupported function.

2. There is also a coder.extrinsic function in MATLAB that allows you to declare the unsupported function as 'extrinsic'. With this option, the code generator produces code for the call to the extrinsic function but does not produce the function's internal code. Therefore, the 'coder.extrinsic' workaround requires that you have the MATLAB Runtime environment on the computer where you are planning to run the generated code.