Merge pull request #40 from zaccharieramzi/vdot

Corrected inner product in restarting FISTA

modopt/opt/algorithms.py

@@ -393,10 +393,7 @@ def is_restart(self, z_old, x_new, x_old):
         """
         if self.restart_strategy is None:
             return False
-        criterion = np.dot(
-            (z_old - x_new).flatten(),
-            (x_new - x_old).flatten(),
-        ) >= 0
+        criterion = np.vdot(z_old - x_new, x_new - x_old) >= 0
         if criterion:
             if 'adaptive' in self.restart_strategy:
                 self.r_lazy *= self.xi_restart