Coder - Create constant for specifying array size

How can I create a constant variable in MATLAB (and its results the generated C code), so I can use it later in my code to specify the size of variables.

In C, we usually do this:

const int arraySize = 5;

int array[arraySize];

When I write the following in the MATLAB, coder just repalces arraySize with the actual number which is 5:

arraySize=5;
array=zeros(1,arraySize); % zeros is just used for specifying size 

(This array size may be repeated throughout the different functions and code many times, so global probably may be related to this)

I want to use static memory allocation as long as it is possible.

Related also to this question: https://www.mathworks.com/matlabcentral/answers/84419-declaring-const-variable-in-generated-code

Answer 1

[Fangjun Jiang]

Please refer to the document

Code Generation for Variable-Size Arrays

web(fullfile(docroot, 'simulink/ug/what-is-variable-size-data.html'))

Control Memory Allocation for Variable-Size Arrays in a MATLAB FunctionBlock

web(fullfile(docroot, 'ecoder/ug/control-memory-allocation-for-variable-size-arrays-in-a-matlab-function-block.html'))

[amin ya]

This is not useful.

I want to have an array that its size is not hardcoded via number all over the code. This may be related to constant folding which I can not disable!

I want to specify the size at the beginning of the code like how we do in C code using one of the followings:

constant int arraySize=5

or

#define arraysize 5

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For example the generated code for my This example, where a is defined as a global constant int8(5),

function A=coder()

global a
A=zeros(a,a);

end

is this, which you see 5 is used in the code instead of being defined in the beginning

#include <string.h>
#include "coder.h"

void coder(double A[5][5])
{
  memset(&A[0][0], 0, sizeof(double) << 16);
}

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I tried using the following but it does not allow me to use a in MATLAB calculations:

a=coder.opaque('const int16','5');
A=zeros(a,a);