Write a function myadd that returns the sum of its inputs.

function c = myadd(a,b)
c = a + b;
end

Create a configuration object for MEX code generation.

mexcfg = coder.config('mex');

Look at the value of the constant input checking configuration parameter.

mexcfg.ConstantInputs

ans =

    'CheckValues'

It has the default value.

Generate a MEX function myadd_mex. Specify that the first argument is a double scalar and the second argument is a constant with value 3.

codegen myadd -config mexcfg -args {1, coder.Constant(3)}

Call myadd_mex. You must provide the input 3 for the second argument.

myadd_mex(1,3)

ans =

    4

Modify ConstantInputs so that the MEX function does not check that the input value matches the value specified at code generation time.

mexcfg.ConstantInputs = 'IgnoreValues';

Generate myadd_mex.

codegen myadd -config mexcfg -args {1, coder.Constant(3)}

Call myadd_mex with a constant input value other than 3, for example 5.

myadd_mex(1,5)

ans =

    4

The MEX function ignores the input value 5. It uses the value 3, which is the value that you specified for the constant argument b when you generated myadd_mex.

Modify ConstantInputs so that the MEX function signature does not include the constant input argument.

mexcfg.ConstantInputs = 'Remove';

Generate myadd_mex.

codegen myadd -config mexcfg -args {1, coder.Constant(3)}

Call myadd_mex. Provide the value 1 for a. Do not provide a value for the constant argument b.

myadd_mex(1)

ans =

    4

Write a function identity that copies its input to its output.

function y = identity(u) %#codegen
y = u;

Create a code configuration object for C code generation.

cfg = coder.config('lib');

Generate C code for identity with the constant input 42 and generate a report.

codegen identity -config cfg -args {coder.Constant(42)} -report

In the report, on the C code tab, click identity.c.

The function signature for identity is

double identity(void)

Write a function myfunction that returns the value of the global constant g.

function  y = myfunction() %#codegen
global g;

y = g;

end

Create a configuration object for MEX code generation.

cfg = coder.config('mex');

Define a cell array globals that declares that g is a constant global variable with value 5.

globals = {'g', coder.Constant(5)};

Generate a MEX function for myfunction using the -globals option to specify the global data.

codegen -config cfg -globals globals myfunction

Run the generated MEX function.

myfunction_mex

ans =

     5