coder.mustBeComplex

Define entry-point function multiplyByThree that accepts a complex single-precision scalar input.

function out = multiplyByThree(in)
arguments
    in (1,1) single {coder.mustBeComplex}
end
out = in*3;
end

Generate a static library for multiplyByThree using the codegen command. Because the arguments block fully specifies the type, size, and complexity of the input argument in, you do not need to use the -args option.

codegen -config:lib -c multiplyByThree -report

Code generation successful: View report

Open the code generation report. Observe that the input argument in has a complex type.

Define the entry-point function testComplex that calls the local function local. The function local accepts one input that is declared to be complex using the coder.mustBeComplex validator.

function y = testComplex(x)
y = local(x);
end

function v = local(u)
arguments
    u {coder.mustBeComplex}
end
v = u + sqrt(u);
end

Attempt to generate code for the testComplex function. Specify the input to be a scalar double using the -args option. Code generation fails because the code generator treats the input to testComplex as real by default. You pass this real type directly to local, thereby triggering an error from the coder.mustBeComplex validator.

codegen testComplex -args 0

Value must be complex.

Error in ==> testComplex Line: 7 Column: 8
Code generation failed: View Error Report

To fix this issue, convert the input x to testComplex to a complex type before passing it to local using the complex function.

function y = testComplex(x)
y = local(complex(x));
end

function v = local(u)
arguments
    u {coder.mustBeComplex}
end
v = u + sqrt(u);
end

Run the same codegen command again.

codegen testComplex -args 0

Code generation successful.