how to display / recall data in matlab

i have such a long code that is really hard to reverse engineer for what i need.

i just need a code that would display which variables that have been used that calculate the matrix.

example:-

A=[10 20 30 40 50]

B= (A.*2)+1 %irreversable code

C=B(B > 40 & B < 80)

C= 41 61 81

D= 20 30 40

to elaborate furthur, i have an array of inputs, 27 elements to be exact, placed into many if conditions

and equations, now i need to know which inputs have passed all my if conditions,(REVERSE ENGINEER)

[Rik]

What do you mean? What is your end goal? Can you give a bit more context to your question?

Editing your question will automatically reopen it.

[Rik]

So you mean you need to deduce which elements from A are still present in D?

It sounds like your code should be better structured to allow for something like this, instead of treating your own code as a black box.

[omar mahallawy]

yes, which elements from A are present in D

noted,for your info this is my first project on matlab, and it is pretty complicated.

Answer 1

[Rik]

As long as the input array A has sufficiently unique values, you can use either ismember or ismembertol.

A=[10 20 30 40 50]
blackbox=@(x) x(x*2+1 > 40 & x*2+1 < 80);
D=blackbox(A);

tol=1e-6;%use an absolute tolerance to account for float rounding
L=ismembertol(A,D,tol,'DataScale',1);
%exp(log(3))==3 will return false, ismembertol can account for this
%L contains the positions in A where it shares elements with D

Note that your code example is incorrect, since C would not contain 81, as that is larger than 80, not smaller.

[Rik]

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Answer 2

[TADA]

Seems To Me Like What You Want Is To Keep Track Of All Your If Conditions With A Logical Index

index = B > 40 & B < 80;

% your next conditions go here
index = index & ~isnan(B); % obviously this condition makes no sence, but I'm improvising

C = B(index);
D = A(index);