Trouble creating function out of variable in terms of x

For my project, I need to create a polynomial using divided differences. I sucessfuly can create the polynomial, but I do not know how to turn this polynomial into a funcion. I created this polynomial by adding to matrices together.

 
    E= sym(zeros(n,1));
  
    b=2;
    d=1;
    if b<n
        for a=1:1:n
            p=(x-B(1,a));
            d=p*d;
            E(a,1)=d;
            
        end
        b=b+1;
    end
    
    F= sym(zeros(n,1));
    m=1;
while m<n+1
        if m<2
        F(m,1) = C(m,1);
        end
    
        if m>1
        F(m,1) = C(m,1)*E(m,1);
       
        end
        m=m+1;
end
    

w=1;
poly=0;
while w<n+1
    addon=F(w,1);
    poly=poly+addon;

    w=w+1;
end
 

[John Phelan]

I get a correct polynomial ouput for "poly", but I cannot plug in an x term for poly. For example, poly(2) does not work. I am pretty sure that this is just because of the type of variable I am using.

Also I take numbers from matrices B and C which I do not include here.

Answer 1

[Peter O]

Is there any particular reason it needs to be using symbolic math?

MATLAB has a built-in polynomial evaluation function called polyval. See if you can structure your problem to take advantage of that for evaluation.

[John Phelan]

I am not purposely using symbolic math. To be honest, I am very new to using MAT LAB.

However, I am not sure if using polyval is the best approach here. For my x values, I need them in the form (x-1)*(x-2)... etc. So I don't think it would be easy to covert that to the form needed for polyval

I am wondering how I can convert my answer in terms of x variables to the correct form that can be turned into a function.