Some of my variables are not initialized when converted to C using Coder

I am trying to learn Matlab Coder using the tutorials and example files.

When I convert the following .m code into C++ code using Matlab Coder the block of code addressing x_est and p_est is ignored as seen in the generated C++ code that follows. I have looked through all of the other accompying files created by Coder and it is not addressed in any of them either. Is there a reason for this?

** Matlab .m code:

%   Copyright 2010 The MathWorks, Inc.
function y = Temp(z) 
%#codegen

persistent x_est p_est               % Initial state conditions
if isempty(x_est)
    x_est = zeros(6, 1);             % x_est=[x,y,Vx,Vy,Ax,Ay]'
    p_est = zeros(6, 6);
end

% Pre-allocate output signal:
y=zeros(size(z));

end                % of the function

** Matlab Coder C++ generated code:

/*
 * Temp.c
 *
 * Code generation for function 'Temp'
 *
 * C source code generated on: Tue Dec 04 15:45:49 2012
 *
 */

/* Include files */
#include "rt_nonfinite.h"
#include "Temp.h"

/*
 * function y = Temp(z)
 */
void Temp(const real_T z[10], real_T y[10])
{

    memset(&y[0], 0, 10U * sizeof(real_T));

    /*  of the function */
  }

/* End of code generation (Temp.c) */

Answer 1

[Arnab De]

The variables x_est and p_est are not used in the MATLAB code. Therefore the compiler eliminates them.