Fixed PowerSpace.total_volume. Moved memoization.py to package directory root.

nifty/__init__.py

@@ -46,6 +46,8 @@ from .field_types import *
 
 from .energies import *
 
+from .memoization import memo
+
 from .minimization import *
 
 from .spaces import *

nifty/energies/__init__.py

@@ -19,4 +19,3 @@
 from .energy import Energy
 from .quadratic_energy import QuadraticEnergy
 from .line_energy import LineEnergy
-from .memoization import memo

nifty/energies/energy.py

@@ -17,7 +17,7 @@
 # and financially supported by the Studienstiftung des deutschen Volkes.
 
 from ..nifty_meta import NiftyMeta
-from .memoization import memo
+from ..memoization import memo
 
 from keepers import Loggable
 from future.utils import with_metaclass

nifty/energies/quadratic_energy.py

 from .energy import Energy
-from .memoization import memo
+from ..memoization import memo
 
 
 class QuadraticEnergy(Energy):

nifty/library/critical_filter/critical_power_energy.py

@@ -2,7 +2,7 @@ from ...energies.energy import Energy
 from ...operators.smoothness_operator import SmoothnessOperator
 from ...operators.diagonal_operator import DiagonalOperator
 from . import CriticalPowerCurvature
-from ...energies.memoization import memo
+from ...memoization import memo
 from ...minimization import ConjugateGradient
 
 from ...sugar import generate_posterior_sample

nifty/library/log_normal_wiener_filter/log_normal_wiener_filter_curvature.py

 from ...operators import EndomorphicOperator,\
                             InvertibleOperatorMixin
-from ...energies.memoization import memo
+from ...memoization import memo
 from ...basic_arithmetics import clipped_exp
 from ...sugar import create_composed_fft_operator
 from ...minimization import ConjugateGradient

nifty/library/wiener_filter/wiener_filter_energy.py

 from ...energies.energy import Energy
-from ...energies.memoization import memo
+from ...memoization import memo
 from ...minimization import ConjugateGradient
 
 from . import WienerFilterCurvature

nifty/spaces/power_space/power_space.py

@@ -21,6 +21,7 @@ import numpy as np
 from d2o import distributed_data_object,\
     STRATEGIES as DISTRIBUTION_STRATEGIES
 
+from ...memoization import memo
 from ...spaces.space import Space
 from functools import reduce
 from ...config import nifty_configuration as gc
@@ -187,9 +188,9 @@ class PowerSpace(Space):
         return self.shape[0]
 
     @property
+    @memo
     def total_volume(self):
-        # every power-pixel has a volume of 1
-        return float(reduce(lambda x, y: x*y, self.pindex.shape))
+        return np.sum(self._volume_weight)
 
     def copy(self):
         distribution_strategy = self.pindex.distribution_strategy
@@ -198,15 +199,7 @@ class PowerSpace(Space):
                               binbounds=self._binbounds)
 
     def weight(self, x, power, axes, inplace=False):
-        try:
-            weight = self._volume_weight
-        except AttributeError:
-            from ...field import Field
-            weight_field = Field(domain=self.harmonic_partner, val=1).weight()
-            self._volume_weight = \
-                self.pindex.bincount(weights=weight_field.val).get_full_data()
-            weight = self._volume_weight
-
+        weight = self._volume_weight
         reshaper = [1, ] * len(x.shape)
         # we know len(axes) is always 1
         reshaper[axes[0]] = self.shape[0]
@@ -223,6 +216,13 @@ class PowerSpace(Space):
 
         return result_x
 
+    @property
+    @memo
+    def _volume_weight(self):
+        from ...field import Field
+        weight_field = Field(domain=self.harmonic_partner, val=1).weight()
+        return self.pindex.bincount(weights=weight_field.val).get_full_data()
+
     def get_distance_array(self, distribution_strategy):
         return distributed_data_object(
                                 self.kindex, dtype=np.float64,