MATLAB Coder does not recognize dot notation in struct member assignment

% Unable to generate C Code using MATLAB Coder for simplified example function shown below. Error description states, "This assignment

% writes a 'double' value into a 'struct' type. Code generation does not support changing types through assignment. Check preceding

% assignment or input type specifications for type mismatches ".

function ExampleFunction() %#codegen

global SD

SD.a = 0.0;

SD.b = 1.0;

SD.a = SD.b;

end

[Konstantinos Athanasiou]

Hi Aaron. Could you provide the codegen command you are using for the above example?

Answer 1

[Benjamin Thompson]

See the article "Name the C Structure Type to Use With a Global Structure Variable" in the MATLAB help documentation. You need to register the struct type with coder and map struct variables to registered types.

Answer 2

[Konstantinos Athanasiou]

The following codegen command compiles without errors for the provided example.

% codegen t -globals {'SD', struct('a', double(0), 'b', double(0))}
function r = t
    global SD;
    SD.a = 0.1;
    SD.b = 0.2;
    SD.a = SD.b;
    r = SD.a;
end