function g = rosegrad(x)%ROSEGRAD Calculate gradient of Rosenbrock's function.%%	Description%	G = ROSEGRAD(X) computes the gradient of Rosenbrock's function at%	each row of X, which should have two columns.%%	See also%	DEMOPT1, ROSEN%%	Copyright (c) Ian T Nabney (1996-2001)% Return gradient of Rosenbrock's test functionnrows = size(x, 1);g = zeros(nrows,2);g(:,1) = -400 * (x(:,2) - x(:,1).^2) * x(:,1) - 2 * (1 - x(:,1));g(:,2) = 200 * (x(:,2) - x(:,1).^2);