Where is dlfeval tracing information stored?

When dlfeval() is used to call a function, the computation is traced in such a way as to later allow automatic differentiation via dlgradient(). For example,

 x=dlarray(rand(30)); 
 f=@(x) sum(x*x'*x*x'*x*x'*x*x'*x*x'*x*x'*x*x'); 
 y1=f(x); 
 y2=dlfeval(f,x); 

My question is, where is this tracing information stored? In y2? If so, why does whos() not show any apparent additional memory consumption by y2, as compared to the untraced version y1?

  whos y1 y2

  Name      Size            Bytes  Class      Attributes

  y1        1x30              240  dlarray              
  y2        1x30              240  dlarray              

Answer 1

[Bruno Luong]

I don't kwow the dlarray class but IMO it looks like the creating function handle f is stored in some sort of private property in y2 well hidden and cannot be disclosed by whos command.