+function f = rosenbrock1(x)
+ ##
+ ## A version of the Rosenbrock function which takes a column
+ ## 2-vector instead of two distinct arguments. See rosenbrock.m for
+ ## more information.
+ ##
+ if (length(x) == 2)
+ f = rosenbrock(x(1), x(2));
+ else
+ f = NA;
+ end
+end