function y = rosen(x)
%ROSEN Calculate Rosenbrock's function.
% Y = ROSEN(X) computes the value of Rosenbrock's function at each row
% of X, which should have two columns.
% See also
% DEMOPT1, ROSEGRAD
% Copyright (c) Ian T Nabney (1996-2001)
% Calculate value of Rosenbrock's function: x should be nrows by 2 columns
y = 100 * ((x(:,2) - x(:,1).^2).^2) + (1.0 - x(:,1)).^2;