Merge branch 'total_volume' into 'NIFTy_5'

Add total_volume property to DomainTuple

See merge request !359

nifty5/domain_tuple.py

@@ -19,6 +19,8 @@ from functools import reduce
 from . import utilities
 from .domains.domain import Domain
 
+import numpy as np
+
 
 class DomainTuple(object):
     """Ordered sequence of Domain objects.
@@ -125,6 +127,58 @@ class DomainTuple(object):
         """
         return self._size
 
+    def scalar_weight(self, spaces=None):
+        """Returns the uniform volume element for a sub-domain of `self`.
+
+        Parameters
+        ----------
+        spaces : int, tuple of int or None
+            Indices of the sub-domains to be considered.
+            If `None`, the entire domain is used.
+
+        Returns
+        -------
+        float or None
+            If the requested sub-domain has a uniform volume element, it is
+            returned. Otherwise, `None` is returned.
+        """
+        if np.isscalar(spaces):
+            return self._dom[spaces].scalar_dvol
+
+        if spaces is None:
+            spaces = range(len(self._dom))
+        res = 1.
+        for i in spaces:
+            tmp = self._dom[i].scalar_dvol
+            if tmp is None:
+                return None
+            res *= tmp
+        return res
+
+    def total_volume(self, spaces=None):
+        """Returns the total volume of `self` or of a subspace of it.
+
+        Parameters
+        ----------
+        spaces : int, tuple of int or None
+            Indices of the sub-domains of the domain to be considered.
+            If `None`, the total volume of the whole domain is returned.
+
+        Returns
+        -------
+        float
+            the total volume of the requested (sub-)domain.
+        """
+        if np.isscalar(spaces):
+            return self._dom[spaces].total_volume
+
+        if spaces is None:
+            spaces = range(len(self._dom))
+        res = 1.
+        for i in spaces:
+            res *= self._dom[i].total_volume
+        return res
+
     @property
     def axes(self):
         """tuple of tuple of int : axis indices of the underlying domains"""

nifty5/field.py

@@ -246,42 +246,23 @@ class Field(object):
             If the requested sub-domain has a uniform volume element, it is
             returned. Otherwise, `None` is returned.
         """
-        if np.isscalar(spaces):
-            return self._domain[spaces].scalar_dvol
-
-        if spaces is None:
-            spaces = range(len(self._domain))
-        res = 1.
-        for i in spaces:
-            tmp = self._domain[i].scalar_dvol
-            if tmp is None:
-                return None
-            res *= tmp
-        return res
+        return self._domain.scalar_weight(spaces)
 
     def total_volume(self, spaces=None):
-        """Returns the total volume of a sub-domain of `self`.
+        """Returns the total volume of the field's domain or of a subspace of it.
 
         Parameters
         ----------
         spaces : int, tuple of int or None
             Indices of the sub-domains of the field's domain to be considered.
-            If `None`, the entire domain is used.
+            If `None`, the total volume of the whole domain is returned.
 
         Returns
         -------
         float
-            the total volume of the requested sub-domain.
+            the total volume of the requested (sub-)domain.
         """
-        if np.isscalar(spaces):
-            return self._domain[spaces].total_volume
-
-        if spaces is None:
-            spaces = range(len(self._domain))
-        res = 1.
-        for i in spaces:
-            res *= self._domain[i].total_volume
-        return res
+        return self._domain.total_volume(spaces)
 
     def weight(self, power=1, spaces=None):
         """Weights the pixels of `self` with their invidual pixel volumes.

test/test_field.py

@@ -219,17 +219,23 @@ def test_weight():
     f = ift.Field.full(s1, 10.)
     f2 = f.weight(1)
     assert_equal(f.weight(1).local_data, f2.local_data)
+    assert_equal(f.domain.total_volume(), 1)
+    assert_equal(f.domain.total_volume(0), 1)
+    assert_equal(f.domain.total_volume((0,)), 1)
     assert_equal(f.total_volume(), 1)
     assert_equal(f.total_volume(0), 1)
     assert_equal(f.total_volume((0,)), 1)
+    assert_equal(f.domain.scalar_weight(), 0.1)
+    assert_equal(f.domain.scalar_weight(0), 0.1)
+    assert_equal(f.domain.scalar_weight((0,)), 0.1)
     assert_equal(f.scalar_weight(), 0.1)
     assert_equal(f.scalar_weight(0), 0.1)
     assert_equal(f.scalar_weight((0,)), 0.1)
     s1 = ift.GLSpace(10)
     f = ift.Field.full(s1, 10.)
-    assert_equal(f.scalar_weight(), None)
-    assert_equal(f.scalar_weight(0), None)
-    assert_equal(f.scalar_weight((0,)), None)
+    assert_equal(f.domain.scalar_weight(), None)
+    assert_equal(f.domain.scalar_weight(0), None)
+    assert_equal(f.domain.scalar_weight((0,)), None)
 
 
 @pmp('dom', [ift.RGSpace(10), ift.GLSpace(10)])