How to add power of x from 0 to n-1

I have a function vandermonde

function c = vandermonde(x, y)
    V = [x.^0 x x.^2 x.^3]  
    c = V \ y;
end

it works good if I give a vector x with 4 components. But how could I make it general, even if I give a vector x with 5,6 or even 15 components? so that V = [x.^0 x x.^2 x.^3 x.^4 x.^5 .... x.^14] ? with n or something like that?

Answer 1

[Matt J]

   V=bsxfun(@power,x(:),0:n-1)

[Matt J]

Of course, I hope you are not using this as a substitute for POLYFIT.

[Karim Belkhiria]

thank you for your answer! It works! but we are not allowed to use bsxfun and @power. It is a homework, and we are beginners with matlab. it should be something really simple with the basics of MATLAB. Is there any other solution with "basic" commands?

[Matt J]

Yes, perhaps. But it is your homework...

Answer 2

[Karim Belkhiria]

here is the answer that I searched for:

function c = vmonde(x, y)
   n = length(x);
   V = ones(n);
   for j = 2:n
        V(:,j) = x.*V(:,j-1);
   end
    c = V \ y;
    disp(V)
end

[Matt J]

I wonder if your teacher would also have accepted this

   V=exp(log(x(:))*(0:n-1))