DatView: Fix zero() (#727)

pyop2/types/dat.py

@@ -681,6 +681,7 @@ def __init__(self, dat, index):
             if not (0 <= i < d):
                 raise ex.IndexValueError("Can't create DatView with index %s for Dat with shape %s" % (index, dat.dim))
         self.index = index
+        self._idx = (slice(None), *index)
         self._parent = dat
         # Point at underlying data
         super(DatView, self).__init__(dat.dataset,
@@ -720,41 +721,37 @@ def halo_valid(self):
     def halo_valid(self, value):
         self._parent.halo_valid = value
 
+    @property
+    def dat_version(self):
+        return self._parent.dat_version
+
+    @property
+    def _data(self):
+        return self._parent._data[self._idx]
+
     @property
     def data(self):
-        full = self._parent.data
-        idx = (slice(None), *self.index)
-        return full[idx]
+        return self._parent.data[self._idx]
 
     @property
     def data_ro(self):
-        full = self._parent.data_ro
-        idx = (slice(None), *self.index)
-        return full[idx]
+        return self._parent.data_ro[self._idx]
 
     @property
     def data_wo(self):
-        full = self._parent.data_wo
-        idx = (slice(None), *self.index)
-        return full[idx]
+        return self._parent.data_wo[self._idx]
 
     @property
     def data_with_halos(self):
-        full = self._parent.data_with_halos
-        idx = (slice(None), *self.index)
-        return full[idx]
+        return self._parent.data_with_halos[self._idx]
 
     @property
     def data_ro_with_halos(self):
-        full = self._parent.data_ro_with_halos
-        idx = (slice(None), *self.index)
-        return full[idx]
+        return self._parent.data_ro_with_halos[self._idx]
 
     @property
     def data_wo_with_halos(self):
-        full = self._parent.data_wo_with_halos
-        idx = (slice(None), *self.index)
-        return full[idx]
+        return self._parent.data_wo_with_halos[self._idx]
 
 
 class Dat(AbstractDat, VecAccessMixin):

test/unit/test_dats.py

@@ -55,6 +55,16 @@ def mdat(d1):
     return op2.MixedDat([d1, d1])
 
 
+@pytest.fixture(scope='module')
+def s2(s):
+    return op2.DataSet(s, 2)
+
+
+@pytest.fixture
+def vdat(s2):
+    return op2.Dat(s2, np.zeros(2 * nelems), dtype=np.float64)
+
+
 class TestDat:
 
     """
@@ -254,6 +264,60 @@ def test_accessing_data_with_halos_increments_dat_version(self, d1):
         assert d1.dat_version == 1
 
 
+class TestDatView():
+
+    def test_dat_view_assign(self, vdat):
+        vdat.data[:, 0] = 3
+        vdat.data[:, 1] = 4
+        comp = op2.DatView(vdat, 1)
+        comp.data[:] = 7
+        assert not vdat.halo_valid
+        assert not comp.halo_valid
+
+        expected = np.zeros_like(vdat.data)
+        expected[:, 0] = 3
+        expected[:, 1] = 7
+        assert all(comp.data == expected[:, 1])
+        assert all(vdat.data[:, 0] == expected[:, 0])
+        assert all(vdat.data[:, 1] == expected[:, 1])
+
+    def test_dat_view_zero(self, vdat):
+        vdat.data[:, 0] = 3
+        vdat.data[:, 1] = 4
+        comp = op2.DatView(vdat, 1)
+        comp.zero()
+        assert vdat.halo_valid
+        assert comp.halo_valid
+
+        expected = np.zeros_like(vdat.data)
+        expected[:, 0] = 3
+        expected[:, 1] = 0
+        assert all(comp.data == expected[:, 1])
+        assert all(vdat.data[:, 0] == expected[:, 0])
+        assert all(vdat.data[:, 1] == expected[:, 1])
+
+    def test_dat_view_halo_valid(self, vdat):
+        """Check halo validity for DatView"""
+        comp = op2.DatView(vdat, 1)
+        assert vdat.halo_valid
+        assert comp.halo_valid
+        assert vdat.dat_version == 0
+        assert comp.dat_version == 0
+
+        comp.data_ro_with_halos
+        assert vdat.halo_valid
+        assert comp.halo_valid
+        assert vdat.dat_version == 0
+        assert comp.dat_version == 0
+
+        # accessing comp.data_with_halos should mark the parent halo as dirty
+        comp.data_with_halos
+        assert not vdat.halo_valid
+        assert not comp.halo_valid
+        assert vdat.dat_version == 1
+        assert comp.dat_version == 1
+
+
 if __name__ == '__main__':
     import os
     pytest.main(os.path.abspath(__file__))