Bug fixes.

nifty/minimization/__init__.py

@@ -18,7 +18,7 @@
 
 from line_searching import *
 from conjugate_gradient import ConjugateGradient
-from descent_minimizer import QuasiNewtonMinimizer
+from descent_minimizer import DescentMinimizer
 from steepest_descent import SteepestDescent
 from vl_bfgs import VL_BFGS
 from relaxed_newton import RelaxedNewton

nifty/minimization/line_searching/line_search_strong_wolfe.py

@@ -148,8 +148,8 @@ class LineSearchStrongWolfe(LineSearch):
 
         # extract the full energy from the line_energy
         energy_star = energy_star.energy
-        length_direction = pk.norm
-        step_length = alpha_star * length_direction
+        direction_length = pk.norm()
+        step_length = alpha_star * direction_length
         return step_length, phi_star, energy_star
 
     def _zoom(self, alpha_lo, alpha_hi, phi_0, phiprime_0,