Merge branch 'fixPSM' into 'master'

[FIX] PSM generation

See merge request pycodegen/lbmpy!180

src/lbmpy/methods/abstractlbmethod.py

@@ -124,7 +124,8 @@ class AbstractLbMethod(abc.ABC):
         substitutions = [Assignment(e[1], e[0]) for e in subexpressions.items()]
         if relaxation_rates_modifier is not None:
             symbolic_relaxation_rates = [r * relaxation_rates_modifier for r in symbolic_relaxation_rates]
-        for srr in symbolic_relaxation_rates:
-            assert isinstance(srr, sp.Symbol)
+        else:
+            for srr in symbolic_relaxation_rates:
+                assert isinstance(srr, sp.Symbol)
 
         return substitutions, sp.diag(*symbolic_relaxation_rates)

tests/test_psm.py

+import pytest
+import numpy as np
+
+from pystencils import fields, CreateKernelConfig, Target, create_kernel, get_code_str, create_data_handling
+from lbmpy import LBMConfig, Stencil, Method, LBStencil, create_lb_method, create_lb_collision_rule, LBMOptimisation, \
+    create_lb_update_rule
+from lbmpy.partially_saturated_cells import PSMConfig
+
+
+@pytest.mark.parametrize("stencil", [Stencil.D2Q9, Stencil.D3Q19, Stencil.D3Q27])
+@pytest.mark.parametrize("method_enum", [Method.SRT, Method.MRT, Method.CUMULANT])
+def test_psm_integration(stencil, method_enum):
+    stencil = LBStencil(stencil)
+
+    fraction_field = fields("fraction_field: double[10, 10, 5]", layout=(2, 1, 0))
+    object_vel = fields("object_vel(3): double[10, 10, 5]", layout=(3, 2, 1, 0))
+    psm_config = PSMConfig(fraction_field=fraction_field, object_velocity_field=object_vel)
+
+    lbm_config = LBMConfig(stencil=stencil, method=method_enum, relaxation_rate=1.5, compressible=True,
+                           psm_config=psm_config)
+    config = CreateKernelConfig(target=Target.CPU)#
+
+    collision_rule = create_lb_collision_rule(lbm_config=lbm_config)
+
+    ast = create_kernel(collision_rule, config=config)
+    code_str = get_code_str(ast)
+
+
+def get_data_handling_for_psm(use_psm):
+    domain_size = (10, 10)
+    stencil = LBStencil(Stencil.D2Q9)
+    dh = create_data_handling(domain_size=domain_size, periodicity=(True, False))
+
+    f = dh.add_array('f', values_per_cell=len(stencil))
+    dh.fill(f.name, 0.0, ghost_layers=True)
+    f_tmp = dh.add_array('f_tmp', values_per_cell=len(stencil))
+    dh.fill(f_tmp.name, 0.0, ghost_layers=True)
+
+    psm_config = None
+    if use_psm:
+        fraction_field = dh.add_array('fraction_field', values_per_cell=1)
+        dh.fill(fraction_field.name, 0.0, ghost_layers=True)
+        object_vel = dh.add_array('object_vel', values_per_cell=dh.dim)
+        dh.fill(object_vel.name, 0.0, ghost_layers=True)
+        psm_config = PSMConfig(fraction_field=fraction_field, object_velocity_field=object_vel)
+
+    lbm_config = LBMConfig(stencil=stencil, method=Method.SRT, relaxation_rate=1.5, psm_config=psm_config)
+
+    lbm_optimisation = LBMOptimisation(symbolic_field=f, symbolic_temporary_field=f_tmp)
+    update_rule = create_lb_update_rule(lbm_config=lbm_config, lbm_optimisation=lbm_optimisation)
+    kernel_lb_step_with_psm = create_kernel(update_rule).compile()
+    return (dh, kernel_lb_step_with_psm)
+
+
+def test_lbm_vs_psm():
+
+    psm_dh, psm_kernel = get_data_handling_for_psm(True)
+    lbm_dh, lbm_kernel = get_data_handling_for_psm(False)
+
+    for i in range(20):
+        psm_dh.run_kernel(psm_kernel)
+        psm_dh.swap('f', 'f_tmp')
+
+        lbm_dh.run_kernel(lbm_kernel)
+        lbm_dh.swap('f', 'f_tmp')
+
+    max_vel_error = np.max(np.abs(psm_dh.gather_array('f') - lbm_dh.gather_array('f')))
+    np.testing.assert_allclose(max_vel_error, 0, atol=1e-14)