Code Generation for Strings - MATLAB & Simulink (original) (raw)

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Code generation supports 1-by-1 MATLAB® string arrays. Code generation does not support string arrays that have more than one element.

A 1-by-1 string array, called a string scalar, contains one piece of text, represented as a 1-by-n character vector. An example of a string scalar is "Hello, world". For more information about strings, see Text in String and Character Arrays.

Limitations

For string scalars, code generation does not support:

• Global variables
• Indexing with curly braces {}
• Missing values
• Defining input types programmatically by using preconditioning withassert statements
• Their use with coder.varsize, when generating code by using the codegen command, thefiaccel (Fixed-Point Designer) command, or the MATLAB Coder™ app
• Their use as Simulink® signals, parameters, or data store memory

For code generation, limitations that apply to classes apply to strings. See MATLAB Classes Definition for Code Generation.

Differences Between Generated Code and MATLAB Code

• Converting a string that contains multiple unary operators todouble can produce different results between MATLAB and the generated code. Consider this function:
  function out = foo(op)
  out = double(op + 1);
  end
  For an input value "--", the function converts the string "--1" to double. In MATLAB, the answer is NaN. In the generated code, the answer is 1.
• Double conversion for a string with misplaced commas (commas that are not used as thousands separators) can produce different results from MATLAB.

Related Topics

• Specify String Scalar Inputs at the Command Line