From c1721980a1c2d5c7a9f1ae65181e4a51129700da Mon Sep 17 00:00:00 2001
From: Martin Bauer <martin.bauer@fau.de>
Date: Fri, 16 Nov 2018 10:36:50 +0100
Subject: [PATCH] New function to create LB equilibrium from initial values
assignments
---
lbstep.py | 17 ++++++-----------
macroscopic_value_kernels.py | 10 ++++++++++
2 files changed, 16 insertions(+), 11 deletions(-)
diff --git a/lbstep.py b/lbstep.py
index c85f2ced..fbb50668 100644
--- a/lbstep.py
+++ b/lbstep.py
@@ -1,10 +1,10 @@
from types import MappingProxyType
-
import numpy as np
from lbmpy.boundaries.boundaryhandling import LatticeBoltzmannBoundaryHandling
from lbmpy.creationfunctions import switch_to_symbolic_relaxation_rates_for_omega_adapting_methods, \
create_lb_function, update_with_default_parameters
-from lbmpy.macroscopic_value_kernels import create_advanced_velocity_setter_collision_rule
+from lbmpy.macroscopic_value_kernels import create_advanced_velocity_setter_collision_rule, \
+ pdf_initialization_assignments
from lbmpy.simplificationfactory import create_simplification_strategy
from lbmpy.stencils import get_stencil
from pystencils import create_kernel, make_slice, create_data_handling
@@ -389,23 +389,18 @@ class LatticeBoltzmannStep:
def _compile_macroscopic_setter_and_getter(self):
lb_method = self.method
- dim = lb_method.dim
- q = len(lb_method.stencil)
cqc = lb_method.conserved_quantity_computation
pdf_field = self._data_handling.fields[self._pdf_arr_name]
rho_field = self._data_handling.fields[self.density_data_name]
rho_field = rho_field.center if self.density_data_index is None else rho_field(self.density_data_index)
vel_field = self._data_handling.fields[self.velocity_data_name]
- pdf_symbols = [pdf_field(i) for i in range(q)]
- getter_eqs = cqc.output_equations_from_pdfs(pdf_symbols, {'density': rho_field, 'velocity': vel_field})
+ getter_eqs = cqc.output_equations_from_pdfs(pdf_field.center_vector,
+ {'density': rho_field, 'velocity': vel_field})
getter_kernel = create_kernel(getter_eqs, target='cpu', cpu_openmp=self._optimization['openmp']).compile()
- inp_eqs = cqc.equilibrium_input_equations_from_init_values(rho_field, [vel_field(i) for i in range(dim)])
- setter_eqs = lb_method.get_equilibrium(conserved_quantity_equations=inp_eqs)
- setter_eqs = setter_eqs.new_with_substitutions({sym: pdf_field(i)
- for i, sym in enumerate(lb_method.post_collision_pdf_symbols)})
-
+ setter_eqs = pdf_initialization_assignments(lb_method, rho_field,
+ vel_field.center_vector, pdf_field.center_vector)
setter_eqs = create_simplification_strategy(lb_method)(setter_eqs)
setter_kernel = create_kernel(setter_eqs, target='cpu', cpu_openmp=self._optimization['openmp']).compile()
return getter_kernel, setter_kernel
diff --git a/macroscopic_value_kernels.py b/macroscopic_value_kernels.py
index 2e712391..2cdda084 100644
--- a/macroscopic_value_kernels.py
+++ b/macroscopic_value_kernels.py
@@ -4,6 +4,16 @@ from pystencils.field import Field, get_layout_of_array
from lbmpy.simplificationfactory import create_simplification_strategy
+def pdf_initialization_assignments(lb_method, density, velocity, pdfs):
+ """Assignments to initialize the pdf field with equilibrium"""
+ cqc = lb_method.conserved_quantity_computation
+ inp_eqs = cqc.equilibrium_input_equations_from_init_values(density, velocity)
+ setter_eqs = lb_method.get_equilibrium(conserved_quantity_equations=inp_eqs)
+ setter_eqs = setter_eqs.new_with_substitutions({sym: pdfs[i]
+ for i, sym in enumerate(lb_method.post_collision_pdf_symbols)})
+ return setter_eqs
+
+
def compile_macroscopic_values_getter(lb_method, output_quantities, pdf_arr=None, field_layout='numpy', target='cpu'):
"""
Create kernel to compute macroscopic value(s) from a pdf field (e.g. density or velocity)
--
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