KL_Energy: add keyword argument to mirror samples

nifty5/minimization/kl_energy.py

@@ -8,7 +8,8 @@ from .. import utilities
 
 class KL_Energy(Energy):
     def __init__(self, position, h, nsamp, constants=[],
-                 constants_samples=None, _samples=None):
+                 constants_samples=None, mirror_samples=False,
+                 _samples=None):
         super(KL_Energy, self).__init__(position)
         if h.domain is not position.domain:
             raise TypeError
@@ -17,11 +18,14 @@ class KL_Energy(Energy):
         if constants_samples is None:
             constants_samples = constants
         self._constants_samples = constants_samples
+        self._mirror_samples = mirror_samples
         if _samples is None:
             met = h(Linearization.make_partial_var(
                 position, constants_samples, True)).metric
             _samples = tuple(met.draw_sample(from_inverse=True)
                              for _ in range(nsamp))
+            if mirror_samples:
+                _samples += tuple(-s for s in _samples)
         self._samples = _samples
 
         self._lin = Linearization.make_partial_var(position, constants)
@@ -40,7 +44,8 @@ class KL_Energy(Energy):
 
     def at(self, position):
         return KL_Energy(position, self._h, 0, self._constants,
-                         self._constants_samples, self._samples)
+                         self._constants_samples, self._mirror_samples,
+                         self._samples)
 
     @property
     def value(self):