DAMASK_EICMD/python/tests/test_grid_filters.py

import pytest
import numpy as np

from damask import grid_filters

class TestGridFilters:

    def test_cell_coord0(self):
         size = np.random.random(3)
         grid = np.random.randint(8,32,(3))
         coord = grid_filters.cell_coord0(grid,size)
         assert np.allclose(coord[0,0,0],size/grid*.5) and coord.shape == tuple(grid) + (3,)

    def test_node_coord0(self):
         size = np.random.random(3)
         grid = np.random.randint(8,32,(3))
         coord = grid_filters.node_coord0(grid,size)
         assert np.allclose(coord[-1,-1,-1],size) and coord.shape == tuple(grid+1) + (3,)

    def test_coord0(self):
         size = np.random.random(3)
         grid = np.random.randint(8,32,(3))
         c = grid_filters.cell_coord0(grid+1,size+size/grid)
         n = grid_filters.node_coord0(grid,size) + size/grid*.5
         assert np.allclose(c,n)

    @pytest.mark.parametrize('mode',['cell','node'])
    def test_grid_DNA(self,mode):
         """Ensure that xx_coord0_gridSizeOrigin is the inverse of xx_coord0."""
         grid   = np.random.randint(8,32,(3))
         size   = np.random.random(3)
         origin = np.random.random(3)
         coord0 = eval('grid_filters.{}_coord0(grid,size,origin)'.format(mode))                     # noqa
         _grid,_size,_origin = eval('grid_filters.{}_coord0_gridSizeOrigin(coord0.reshape(-1,3,order="F"))'.format(mode))
         assert np.allclose(grid,_grid) and np.allclose(size,_size) and np.allclose(origin,_origin)

    def test_displacement_fluct_equivalence(self):
         """Ensure that fluctuations are periodic."""
         size = np.random.random(3)
         grid = np.random.randint(8,32,(3))
         F    = np.random.random(tuple(grid)+(3,3))
         assert np.allclose(grid_filters.node_displacement_fluct(size,F),
                            grid_filters.cell_2_node(grid_filters.cell_displacement_fluct(size,F)))

    def test_interpolation_nonperiodic(self):
         size = np.random.random(3)
         grid = np.random.randint(8,32,(3))
         F    = np.random.random(tuple(grid)+(3,3))
         assert np.allclose(grid_filters.node_coord(size,F) [1:-1,1:-1,1:-1],grid_filters.cell_2_node(
                            grid_filters.cell_coord(size,F))[1:-1,1:-1,1:-1])

    @pytest.mark.parametrize('mode',['cell','node'])
    def test_coord0_origin(self,mode):
         origin= np.random.random(3)
         size  = np.random.random(3)                                                                # noqa
         grid  = np.random.randint(8,32,(3))
         shifted   = eval('grid_filters.{}_coord0(grid,size,origin)'.format(mode))
         unshifted = eval('grid_filters.{}_coord0(grid,size)'.format(mode))
         if   mode == 'cell':
            assert  np.allclose(shifted,unshifted+np.broadcast_to(origin,tuple(grid)  +(3,)))
         elif mode == 'node':
            assert  np.allclose(shifted,unshifted+np.broadcast_to(origin,tuple(grid+1)+(3,)))

    @pytest.mark.parametrize('function',[grid_filters.cell_displacement_avg,
                                         grid_filters.node_displacement_avg])
    def test_displacement_avg_vanishes(self,function):
         """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(function(size,F),0.0)

    @pytest.mark.parametrize('function',[grid_filters.cell_displacement_fluct,
                                         grid_filters.node_displacement_fluct])
    def test_displacement_fluct_vanishes(self,function):
         """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(function(size,F),0.0)

    @pytest.mark.parametrize('function',[grid_filters.coord0_check,
                                         grid_filters.node_coord0_gridSizeOrigin,
                                         grid_filters.cell_coord0_gridSizeOrigin])
    def test_invalid_coordinates(self,function):
        invalid_coordinates = np.random.random((np.random.randint(12,52),3))
        with pytest.raises(ValueError):
            function(invalid_coordinates)

    @pytest.mark.parametrize('function',[grid_filters.node_coord0_gridSizeOrigin,
                                         grid_filters.cell_coord0_gridSizeOrigin])
    def test_uneven_spaced_coordinates(self,function):
        start = np.random.random(3)
        end   = np.random.random(3)*10. + start
        grid  = np.random.randint(8,32,(3))
        uneven = np.stack(np.meshgrid(np.logspace(start[0],end[0],grid[0]),
                                      np.logspace(start[1],end[1],grid[1]),
                                      np.logspace(start[2],end[2],grid[2]),indexing = 'ij'),
                           axis = -1).reshape((grid.prod(),3),order='F')
        with pytest.raises(ValueError):
            function(uneven)


    @pytest.mark.parametrize('mode',[True,False])
    @pytest.mark.parametrize('function',[grid_filters.node_coord0_gridSizeOrigin,
                                         grid_filters.cell_coord0_gridSizeOrigin])
    def test_unordered_coordinates(self,function,mode):
        origin = np.random.random(3)
        size   = np.random.random(3)*10.+origin
        grid  = np.random.randint(8,32,(3))
        unordered = grid_filters.node_coord0(grid,size,origin).reshape(-1,3)
        if mode:
            with pytest.raises(ValueError):
                function(unordered,mode)
        else:
            function(unordered,mode)

    def test_regrid(self):
         size = np.random.random(3)
         grid = np.random.randint(8,32,(3))
         F    = np.broadcast_to(np.eye(3), tuple(grid)+(3,3))
         assert all(grid_filters.regrid(size,F,grid) == np.arange(grid.prod()))


    @pytest.mark.parametrize('differential_operator',[grid_filters.curl,
                                                      grid_filters.divergence,
                                                      grid_filters.gradient])
    def test_differential_operator_constant(self,differential_operator):
        size = np.random.random(3)+1.0
        grid = np.random.randint(8,32,(3))
        shapes = {
                  grid_filters.curl:      [(3,),(3,3)],
                  grid_filters.divergence:[(3,),(3,3)],
                  grid_filters.gradient:  [(1,),(3,)]
                 }
        for shape in shapes[differential_operator]:
            field = np.ones(tuple(grid)+shape)*np.random.random()*1.0e5
            assert np.allclose(differential_operator(size,field),0.0)


    @pytest.mark.parametrize('field_def,curl_def',
                             [(['np.sin(np.pi*2*nodes[...,2]/size[2])', '0.0', '0.0',
                                '0.0',                                  '0.0', '0.0',
                                '0.0',                                  '0.0', '0.0' ],
                               ['0.0'                                                 , '0.0', '0.0',
                                'np.cos(np.pi*2*nodes[...,2]/size[2])*np.pi*2/size[2]', '0.0', '0.0',
                                '0.0',                                                  '0.0', '0.0']
                              ),
                              (['np.cos(np.pi*2*nodes[...,1]/size[1])', '0.0', '0.0',
                                '0.0',                                  '0.0', '0.0',
                                'np.cos(np.pi*2*nodes[...,0]/size[0])', '0.0', '0.0'],
                               ['0.0',                                                  '0.0', '0.0',
                                '0.0',                                                  '0.0', '0.0',
                                'np.sin(np.pi*2*nodes[...,1]/size[1])*np.pi*2/size[1]', '0.0', '0.0']
                              )
                             ])
    def test_curl(self,field_def,curl_def):
        size = np.random.random(3)+1.0
        grid = np.random.randint(8,32,(3))

        nodes = grid_filters.cell_coord0(grid,size)
        my_locals = locals()                                                                        # needed for list comprehension

        field = np.stack([np.broadcast_to(eval(f,globals(),my_locals),grid) for f in field_def],axis=-1)
        field = field.reshape(tuple(grid) + ((3,3) if len(field_def)==9 else (3,)))
        curl = np.stack([np.broadcast_to(eval(c,globals(),my_locals),grid) for c in curl_def], axis=-1)
        curl = curl.reshape(tuple(grid) + ((3,3) if len(curl_def)==9 else (3,)))

        assert np.allclose(curl,grid_filters.curl(size,field))