How can i find out the gradient of a function with two variables? I have created a symbolic polynomial expression of order two but the gradient function works only on matrices apparently. Is there a two variable equivalent function for sym2poly?

Say the polynomial is f= x^2+y^2-2*x*y+10 with sym var x and y.

[Abhishek Pandey]

I am using MATLAB 2007B and using gradient function with the exact line of code generates an error message..'Error using zeros, trailing string input must be a valid numeric class name'. Jacobian works perfectly though.. Thank you.

[Star Strider]

My pleasure.

If my Answer solved your problem, please Accept it.

Answer 1

[Star Strider]

I am not certain what result you want. Both the gradient and jacobian functions will work for you:

syms x y 
f = x^2 + y^2 - 2*x*y + 10;
Gf = gradient(f, [x y])
Jf = jacobian(f, [x y])

Gf =
 2*x - 2*y
 2*y - 2*x

Jf =
[ 2*x - 2*y, 2*y - 2*x]