remove evaluable.Points,NPoints,Weights (#846)

In an effort to make the `evaluable` module array-only (#738), this PR replaces
and removes the `evaluable.Points`, `.NPoints` and `.Weights` classes.

nutils/__init__.py

@@ -1,4 +1,4 @@
 'Numerical Utilities for Finite Element Analysis'
 
-__version__ = version = '9a11'
+__version__ = version = '9a12'
 version_name = 'jook-sing'

nutils/element.py

@@ -282,7 +282,7 @@ def _linear_cover(self, ctransforms, maxrefine):
         if len(ctransforms) == 1:
             ctrans, = ctransforms
             assert not ctrans
-            return ((), self.getpoints('vertex', maxrefine), allindices),
+            return ((), maxrefine, allindices),
         if maxrefine == 0:
             raise Exception('maxrefine is too low')
         cbins = [set() for ichild in range(self.nchildren)]
@@ -292,9 +292,9 @@ def _linear_cover(self, ctransforms, maxrefine):
         if not all(cbins):
             raise Exception('transformations to not form an element cover')
         fcache = cache.WrapperCache()
-        return tuple(((ctrans,) + trans, points, cindices[indices])
+        return tuple(((ctrans,) + trans, degree, cindices[indices])
                      for ctrans, cref, cbin, cindices in zip(self.child_transforms, self.child_refs, cbins, self.child_divide(allindices, maxrefine))
-                     for trans, points, indices in fcache[cref._linear_cover](frozenset(cbin), maxrefine-1))
+                     for trans, degree, indices in fcache[cref._linear_cover](frozenset(cbin), maxrefine-1))
 
     def __str__(self):
         return self.__class__.__name__

nutils/evaluable.py

@@ -1024,43 +1024,6 @@ def _const_uniform(self):
             return lower if lower == upper else None
 
 
-class NPoints(Array):
-    'The length of the points axis.'
-
-    def __init__(self):
-        super().__init__(args=(EVALARGS,), shape=(), dtype=int)
-
-    @staticmethod
-    def evalf(evalargs):
-        points = evalargs['_points'].coords
-        return types.frozenarray(points.shape[0])
-
-    def _intbounds_impl(self):
-        return 0, float('inf')
-
-
-class Points(Array):
-
-    def __init__(self, npoints, ndim):
-        super().__init__(args=(EVALARGS,), shape=(npoints, ndim), dtype=float)
-
-    @staticmethod
-    def evalf(evalargs):
-        return evalargs['_points'].coords
-
-
-class Weights(Array):
-
-    def __init__(self, npoints):
-        super().__init__(args=(EVALARGS,), shape=(npoints,), dtype=float)
-
-    @staticmethod
-    def evalf(evalargs):
-        weights = evalargs['_points'].weights
-        assert numeric.isarray(weights) and weights.ndim == 1
-        return weights
-
-
 class Orthonormal(Array):
     'make a vector orthonormal to a subspace'
 

nutils/topology.py

@@ -1471,10 +1471,18 @@ def trim(self, levelset, maxrefine, ndivisions=8, name='trimmed', leveltopo=None
                     levels = levelset.eval(_trim_index=ielem, **arguments)
                     refs.append(ref.trim(levels, maxrefine=maxrefine, ndivisions=ndivisions))
         else:
+            # `levelset` is evaluable on `leveltopo`, which must be a uniform
+            # or hierarchical refinement of `self`. Each element of `self` is
+            # trimmed given a sample of `levelset` at the pointset `vertex`
+            # with degree `maxrefine`. This sample is obtained by evaluating
+            # `levelset` for each child element in `leveltopo` at the relevant
+            # subset of the parent sample. Per child element this subset is the
+            # pointset `vertex` with degree `maxrefine` minus the ancestral
+            # level. The mapping from child points to parent points and the
+            # degree of the pointset is provided by `Element._linear_cover`.
             log.info('collecting leveltopo elements')
-            coordinates = evaluable.Points(evaluable.NPoints(), evaluable.constant(self.ndims))
-            ielem = evaluable.Argument('_leveltopo_ielem', (), int)
-            levelset = levelset.lower(function.LowerArgs.for_space(self.space, (leveltopo.transforms, leveltopo.opposites), ielem, coordinates)).optimized_for_numpy
+            lowered_levelset = {}
+            ielem_arg = evaluable.InRange(evaluable.Argument('_ielem', (), int), evaluable.constant(len(leveltopo)))
             bins = [set() for ielem in range(len(self))]
             for trans in leveltopo.transforms:
                 ielem, tail = self.transforms.index_with_tail(trans)
@@ -1487,10 +1495,14 @@ def trim(self, levelset, maxrefine, ndivisions=8, name='trimmed', leveltopo=None
                     # confirm cover and greedily optimize order
                     mask = numpy.ones(len(levels), dtype=bool)
                     while mask.any():
-                        imax = numpy.argmax([mask[indices].sum() for tail, points, indices in cover])
-                        tail, points, indices = cover.pop(imax)
+                        imax = numpy.argmax([mask[indices].sum() for tail, degree, indices in cover])
+                        tail, degree, indices = cover.pop(imax)
                         ielem = leveltopo.transforms.index(trans + tail)
-                        levels[indices] = levelset.eval(_leveltopo_ielem=ielem, _points=points, **arguments)
+                        if degree not in lowered_levelset:
+                            coordinates = leveltopo.references.getpoints('vertex', degree).get_evaluable_coords(ielem_arg)
+                            lower_args = function.LowerArgs.for_space(self.space, (leveltopo.transforms, leveltopo.opposites), ielem_arg, coordinates)
+                            lowered_levelset[degree] = levelset.lower(lower_args).optimized_for_numpy
+                        levels[indices] = lowered_levelset[degree].eval(_ielem=ielem, **arguments)
                         mask[indices] = False
                     refs.append(ref.trim(levels, maxrefine=maxrefine, ndivisions=ndivisions))
             log.debug('cache', fcache.stats)

tests/test_evaluable.py

@@ -755,9 +755,6 @@ def test_inrange_strict(self):
     def test_inrange_empty(self):
         self.assertEqual(evaluable.InRange(self.S('n', float('-inf'), float('inf')), evaluable.constant(0))._intbounds, (0, 0))
 
-    def test_npoints(self):
-        self.assertEqual(evaluable.NPoints()._intbounds, (0, float('inf')))
-
     def test_bool_to_int(self):
         self.assertEqual(evaluable.BoolToInt(evaluable.constant(numpy.array([False, True], dtype=bool)))._intbounds, (0, 1))
 

tests/test_topology.py

@@ -649,9 +649,9 @@ def assertConnectivity(self, domain, geom):
         interfaces = domain.interfaces
         bmask = numpy.zeros(len(boundary), dtype=int)
         imask = numpy.zeros(len(interfaces), dtype=int)
-        coordinates = evaluable.Points(evaluable.NPoints(), evaluable.constant(boundary.ndims))
         edges = domain.transforms.edges(domain.references)
         iedge = evaluable.Argument('_iedge', (), int)
+        coordinates = domain.references.edges.getpoints('gauss', 2).get_evaluable_coords(iedge)
         lowered_geom = geom.lower(function.LowerArgs.for_space(domain.space, (edges,), iedge, coordinates)).simplified
         for ielem, ioppelems in enumerate(domain.connectivity):
             for iedge, ioppelem in enumerate(ioppelems):
@@ -673,9 +673,8 @@ def assertConnectivity(self, domain, geom):
                         self.assertEqual(interfaces.opposites[index], opptrans)
                     imask[index] += 1
                     self.assertEqual(eref, opperef)
-                    points = eref.getpoints('gauss', 2)
-                    a0 = lowered_geom.eval(_iedge=edges.index(trans), _points=points)
-                    a1 = lowered_geom.eval(_iedge=edges.index(opptrans), _points=points)
+                    a0 = lowered_geom.eval(_iedge=edges.index(trans))
+                    a1 = lowered_geom.eval(_iedge=edges.index(opptrans))
                     numpy.testing.assert_array_almost_equal(a0, a1)
         self.assertTrue(numpy.equal(bmask, 1).all())
         self.assertTrue(numpy.equal(imask, 2).all())