coder.getArgTypes

Determine types of function input arguments by executing test file

Syntax

types = coder.getArgTypes(test_fcn,fcn)

struct_of_types = coder.getArgTypes(test_fcn,fcns)

struct_of_types = coder.getArgTypes(test_fcn,fcn,'uniform',struct_flag)

Description

types = coder.getArgTypes(test_fcn,fcn) returns a cell array of coder.Type objects determined by executing test_fcn. The function test_fcn must call the specified entry-point MATLAB^® function fcn. Input arguments to fcn construct the returned types.

struct_of_types = coder.getArgTypes(test_fcn,fcns) returns a structure containing cell arrays of coder.Type objects determined by executing test_fcn. The function test_fcn must call the specified entry-point functions listed in fcns. Input arguments to these functions construct the returned types. The returned structure contains one field for each function. The field name is the same as the name of the corresponding function.

struct_of_types = coder.getArgTypes(test_fcn,fcn,'uniform',struct_flag) returns a structure even though there is only one entry-point function. The property uniform defines whether the output array type is a structure of cell arrays (true) or a cell array (false).

Examples

Get Input Parameter Types for Single Entry-Point Function

Get input parameter types for function my_fun by running test file my_test, which calls my_fun. Use these input types to generate code for my_fun.

In a local writable folder, create the MATLAB function my_fun and save it in the file my_fun.m.

function y = my_fun(u,v) %#codegen
    y = u+v;
end

Create the test function my_test and save it in the file my_test.m.

function y = my_test
    a = single(10);
    b = single(20);
    y = my_fun(a,b);
end

To get the input types for my_fun, run the test function.

types = coder.getArgTypes('my_test','my_fun')

types =

  1×2 cell array

    {1×1 coder.PrimitiveType}    {1×1 coder.PrimitiveType}

Generate a MEX function for my_fun by using these input types as example inputs.

codegen my_fun -args types

In the current folder, codegen generates a MEX function, my_fun_mex, that accepts inputs of type single.

Test the MEX function. For example:

 y = my_fun_mex(single(10),single(20))

Get Input Parameter Types for Multiple Entry-Point Functions

Get input parameter types for functions my_fun1 and my_fun2 by running test file my_test2, which calls my_fun1 and my_fun2. Use these input types to generate code for my_fun1 and my_fun2.

In a local writable folder, create the MATLAB function my_fun1. Save it in the file my_fun1.m.

function y = my_fun1(u) %#codegen
    y = u;

Create the function my_fun2. Save it in the file my_fun2.m.

function y = my_fun2(u,v) %#codegen
    y = u + v;

Create the test function.

function [y1, y2] =  my_test2
    a = 10;
    b = single(20);
    y1 = my_fun1(a);
    y2 = my_fun2(a,b);
end

To get the input types for my_fun1 and my_fun2, run the test function.

types = coder.getArgTypes('my_test2',{'my_fun1','my_fun2'})

types = 

  struct with fields:

    my_fun1: {[1×1 coder.PrimitiveType]}
    my_fun2: {[1×1 coder.PrimitiveType]  [1×1 coder.PrimitiveType]}

Generate a MEX function for my_fun1 and my_fun2 by using these input types as example inputs.

codegen my_fun1 -args types.my_fun1 my_fun2 -args types.my_fun2

In the current folder, codegen generates a MEX function, my_fun1_mex, with two entry points, my_fun1 and my_fun2, that accept inputs of type double.

Test each entry point in the MEX function. For example:

y1 = my_fun1_mex('my_fun1',10)
y2 = my_fun1_mex('my_fun2',10,20)

Get Input Parameter Types as Structure for Single Entry-Point Function

Get input parameter types for function my_fun by running test file my_test, which calls my_fun. Use these input types to generate code for my_fun.

In a local writable folder, create the MATLAB function my_fun and save it in the file my_fun.m.

function y = my_fun(u,v) %#codegen
    y = u+v;
end

Create the test function my_test and save it in the file my_test.m.

function y = my_test
    a = single(10);
    b = single(20);
    y = my_fun(a,b);
end

To get the input types for my_fun as structure with fields, run the test function.

types = coder.getArgTypes('my_test','my_fun','uniform',true)

types =

   struct with fields:

    my_fun: {[1×1 coder.PrimitiveType]  [1×1 coder.PrimitiveType]}

Generate a MEX function for my_fun by using these input types as example inputs.

codegen my_fun -args types.my_fun

In the current folder, codegen generates a MEX function, my_fun_mex, that accepts inputs of type single.

Test the MEX function. For example:

 y = my_fun_mex(single(10),single(20))

Input Arguments

fcn — Name of function

character vector | string scalar | function handle

Name or handle of entry-point MATLAB function for which you want to determine input types. The function cannot be a local function or a function in a namespace. It must be on the MATLAB path in a writable folder.

Example: types = coder.getArgTypes('my_test','my_fun');

Example: types = coder.getArgTypes(@my_test,@my_fun);

Data Types: char | string | function handle

fcns — Names of functions

cell array of character vectors | array of strings | cell array of function handles

Names or handles of entry-point MATLAB functions for which you want to determine input types. The functions cannot be local functions or functions in namespaces. They must be on the MATLAB path in a writable folder. The entry-point function names must be unique.

Example: types = coder.getArgTypes('my_test',{'my_fun1','my_fun2'});

Example: types = coder.getArgTypes(@my_test,{@my_fun1,@my_fun2});

Example: types = coder.getArgTypes("my_test",["my_fun1","my_fun2"});

Data Types: char | string | function handle

test_fcn — Name of test function

character vector | string scalar

Name or handle of test function or name of test script. The test function or script must be on the MATLAB path. test_fcn must call at least one of the specified entry-point functions. The input arguments to these functions construct the returned types.

Example: types = coder.getArgTypes('my_test','my_fun');

Data Types: char | string | function handle

struct_flag — Output array type flag

true | false

true	Returns a structure of cell arrays of coder.Type objects determined by executing test_fcn, even though there is only one entry-point function.
false	Returns a cell array of coder.Type objects determined by executing test_fcn.

Example: coder.getArgTypes('my_test','my_fun','uniform',true);

Data Types: logical

Output Arguments

types — Cell array of coder.Type objects

cell array

Cell array of coder.Type objects determined by executing the test function.

struct_of_types — Structure containing cell arrays of coder.Type objects

struct

Structure containing cell arrays of coder.Type objects determined by executing the test_fcn function. The structure contains one field for each function. The field name is the same as the name of the corresponding function.

Tips

• coder.getArgTypes returns the input types of the function arguments, similar to the Automatically Define Input Types step in the app.

• Before using coder.getArgTypes, run the test function in MATLAB to verify that it provides the expected results.

• Verify that the test function calls the specified entry-point functions with input data types suitable for your run-time environment. If the test function does not call a specified function, coder.getArgTypes cannot determine the input types for this function.

• coder.getArgTypes might not compute the ideal type for your application. For example, you might want the size to be unbounded. The coder.getArgTypes function returns a bound based on the largest input. To adjust the sizes of the returned types, use coder.resize.

• For some combinations of inputs, coder.getArgTypes cannot produce a valid type. For example, if the test function calls the entry-point function with single inputs, and then calls it with double inputs, coder.getArgTypes generates an error because there is no single type that can represent both calls.

• When you generate code for the MATLAB function, use the returned types as example inputs by passing them to the codegen function using the -args option.

Alternatives

• Specify Types of Entry-Point Inputs Using the App

• Specify Input Types Using assert Statements in MATLAB Code

Version History

Introduced in R2012a