Because C and C++ are statically typed languages, at compile time, MATLAB® Coder™ must determine the properties of all variables in the MATLAB files. To infer variable properties in MATLAB files, MATLAB Coder must identify the properties of the inputs to the primary function, also known as the top-level or entry-point function. Therefore, if your primary function has inputs, you must specify the properties of these inputs to MATLAB Coder. If your primary function has no input parameters, you do not need to specify properties of inputs to local functions or external functions called by the primary function.
Unless you use the tilde (~) character to specify unused function inputs, you must specify the same number and order of inputs as the MATLAB function . If you use the tilde character, the inputs default to real, scalar doubles.
Specify an input definition using one of the following methods: