test coordinates-related functions

python/tests/test_grid_filters.py

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+import pytest
+import numpy as np
+
+from damask import grid_filters
+
+class TestGridFilters:
+   
+    def test_coord0_cell(self):
+         size = np.random.random(3)
+         grid = np.random.randint(8,32,(3))
+         coord = grid_filters.coord0_cell(grid,size)
+         assert np.allclose(coord[0,0,0],size/grid*.5) and coord.shape == tuple(grid[::-1]) + (3,)
+
+    def test_coord0_node(self):
+         size = np.random.random(3)
+         grid = np.random.randint(8,32,(3))
+         coord = grid_filters.coord0_node(grid,size)
+         assert np.allclose(coord[-1,-1,-1],size) and coord.shape == tuple(grid[::-1]+1) + (3,)
+
+    def test_coord0(self):
+         size = np.random.random(3)
+         grid = np.random.randint(8,32,(3))
+         c = grid_filters.coord0_cell(grid+1,size+size/grid)
+         n = grid_filters.coord0_node(grid,size) + size/grid*.5
+         assert np.allclose(c,n)
+
+    @pytest.mark.parametrize('mode',[('cell'),('node')])
+    def test_displacement_avg_vanishes(self,mode):
+         """Ensure that random fluctuations in F do not result in average displacement."""
+         size = np.random.random(3)
+         grid = np.random.randint(8,32,(3))
+         F    = np.random.random(tuple(grid)+(3,3))
+         F   += np.eye(3) - np.average(F,axis=(0,1,2))
+         assert np.allclose(eval('grid_filters.displacement_avg_{}(size,F)'.format(mode)),0.0)
+
+    @pytest.mark.parametrize('mode',[('cell'),('node')])
+    def test_displacement_fluct_vanishes(self,mode):
+         """Ensure that constant F does not result in fluctuating displacement."""
+         size = np.random.random(3)
+         grid = np.random.randint(8,32,(3))
+         F    = np.broadcast_to(np.random.random((3,3)), tuple(grid)+(3,3)) 
+         assert np.allclose(eval('grid_filters.displacement_fluct_{}(size,F)'.format(mode)),0.0)