Ordinary Least Squares Method program

I have to make form scratch a program that applies the Ordinary Least Squares Method to a set of data (matrix D) and the base functions( elements of the vector b), but the program isnt working, I think it's not creating the inline functions version of the base functions that I need to calculate the value of those functions on some points, but I don't know how to correct that:

function g=mmq(D,b)

[~,tc]=size(D);
syms x;
for i=1:length(b);
    b(i)=inline(b(i));
end
l=1;
h=1;

A=zeros(length(b),length(b));
while l<=length(b);
    for c=1:length(b);
        while h<=tc;
        A(l,c)=A(l,c)+(b(l)(D(1,h))*b(c)(D(1,h)));
        h=h+1;
        end
    end
    l=l+1;
end
Y=zeros(length(b));
for k=1:length(b);
       while r<=tc;
        Y(l)=Y(l)+(b(k)(D(1,r))*D(2,r));
        r=r+1;
        end
end

Y=Y';
C=A\Y;

for u=1:length(C);
  g=g+(C(u)*b(u));
end

 end