From 580e01bd1c4d02ec2f327d2dfd4f1fc15ccdf269 Mon Sep 17 00:00:00 2001
From: Daniel Otto de Mentock <d.mentock@mpie.de>
Date: Mon, 29 Aug 2022 11:44:50 +0000
Subject: [PATCH] fix grid add primitive bug

---
 python/damask/_grid.py    | 2 +-
 python/tests/test_Grid.py | 9 ++++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/python/damask/_grid.py b/python/damask/_grid.py
index e5c36413f..5810f89c2 100644
--- a/python/damask/_grid.py
+++ b/python/damask/_grid.py
@@ -1206,7 +1206,7 @@ class Grid:
         coords_rot = R.broadcast_to(tuple(self.cells))@coords
 
         with np.errstate(all='ignore'):
-            mask = np.sum(np.power(coords_rot/r,2.0**np.array(exponent)),axis=-1) > 1.0
+            mask = np.sum(np.power(np.abs(coords_rot)/r,2.0**np.array(exponent)),axis=-1) > 1.0
 
         if periodic:                                                                                # translate back to center
             mask = np.roll(mask,((c/self.size-0.5)*self.cells).round().astype(np.int64),(0,1,2))
diff --git a/python/tests/test_Grid.py b/python/tests/test_Grid.py
index 05344d28d..fc1af09b6 100644
--- a/python/tests/test_Grid.py
+++ b/python/tests/test_Grid.py
@@ -299,7 +299,6 @@ class TestGrid:
         G_2 = Grid(np.ones(g,'i'),s,o).add_primitive(diameter,center2,exponent)
         assert np.count_nonzero(G_1.material!=2) == np.count_nonzero(G_2.material!=2)
 
-
     @pytest.mark.parametrize('center',[np.random.randint(4,10,(3)),
                                        np.random.randint(2,10),
                                        np.random.rand()*4,
@@ -315,6 +314,14 @@ class TestGrid:
         G_2 = Grid(np.ones(g,'i'),s).add_primitive(.3,center,1,fill,Rotation.from_random(),inverse,periodic=periodic)
         assert G_1 == G_2
 
+    @pytest.mark.parametrize('exponent',[1,np.inf,np.random.random(3)*2.])
+    def test_add_primitive_shape_symmetry(self,exponent):
+        """Shapes defined in the center should always produce a grid with reflection symmetry along the coordinate axis."""
+        o = np.random.random(3)-.5
+        s = np.random.random(3)*5.
+        grid = Grid(np.zeros(np.random.randint(8,32,3),'i'),s,o).add_primitive(np.random.random(3)*3.,o+s/2.,exponent)
+        for axis in [0,1,2]:
+            assert np.all(grid.material==np.flip(grid.material,axis=axis))
 
     @pytest.mark.parametrize('selection',[1,None])
     def test_vicinity_offset(self,selection):