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import numpy
import time
import matplotlib
matplotlib.use('AGG')
import matplotlib.pyplot as plt
from boltzgen import Generator, Geometry
from boltzgen.lbm.lattice import D2Q9
from boltzgen.lbm.model import BGK
from simulation import Lattice, CellList
def MLUPS(cells, steps, time):
return cells * steps / time * 1e-6
def generate_moment_plots(lattice, moments):
for i, m in enumerate(moments):
print("Generating plot %d of %d." % (i+1, len(moments)))
gid = lattice.memory.gid
velocity = numpy.reshape(
[ numpy.sqrt(m[gid(x,y)*3+1]**2 + m[gid(x,y)*3+2]**2) for x, y in lattice.geometry.inner_cells() ],
lattice.geometry.inner_size())
plt.figure(figsize=(10, 10))
plt.imshow(velocity, origin='lower', cmap=plt.get_cmap('seismic'))
plt.savefig("result/ldc_2d_%02d.png" % i, bbox_inches='tight', pad_inches=0)
nUpdates = 100000
nStat = 10000
geometry = Geometry(256, 256)
print("Generating kernel using boltzgen...\n")
functions = ['collide_and_stream', 'equilibrilize', 'collect_moments', 'momenta_boundary']
extras = ['cell_list_dispatch']
precision = 'single'
generator = Generator(
model = BGK(D2Q9, tau = 0.6),
target = 'cl',
precision = precision,
index = 'ZYX',
layout = 'SOA')
kernel_src = generator.kernel(geometry, functions, extras)
kernel_src += generator.custom(geometry, """
__kernel void equilibrilize(__global ${float_type}* f_next,
__global ${float_type}* f_prev)
{
const unsigned int gid = ${index.gid('get_global_id(0)', 'get_global_id(1)')};
equilibrilize_gid(f_next, f_prev, gid);
}
__kernel void collect_moments(__global ${float_type}* f,
__global ${float_type}* moments)
{
const unsigned int gid = ${index.gid('get_global_id(0)', 'get_global_id(1)')};
collect_moments_gid(f, moments, gid);
}
""")
print("Initializing simulation...\n")
lattice = Lattice(geometry, kernel_src, D2Q9, precision = precision)
gid = lattice.memory.gid
bulk_cells = CellList(lattice.context, lattice.queue, lattice.float_type,
[ gid(x,y) for x, y in geometry.inner_cells() if x > 1 and x < geometry.size_x-2 and y > 1 and y < geometry.size_y-2 ])
wall_cells = CellList(lattice.context, lattice.queue, lattice.float_type,
[ gid(x,y) for x, y in geometry.inner_cells() if x == 1 or y == 1 or x == geometry.size_x-2 ])
lid_cells = CellList(lattice.context, lattice.queue, lattice.float_type,
[ gid(x,y) for x, y in geometry.inner_cells() if y == geometry.size_y-2 ])
lattice.schedule('collide_and_stream_cells', bulk_cells)
lattice.schedule('velocity_momenta_boundary_cells', wall_cells, numpy.array([0.0, 0.0], dtype=lattice.float_type[0]))
lattice.schedule('velocity_momenta_boundary_cells', lid_cells, numpy.array([0.1, 0.0], dtype=lattice.float_type[0]))
print("Starting simulation using %d cells...\n" % lattice.geometry.volume)
moments = []
lastStat = time.time()
for i in range(1,nUpdates+1):
lattice.evolve()
if i % nStat == 0:
lattice.sync()
print("i = %4d; %3.0f MLUPS" % (i, MLUPS(lattice.geometry.volume, nStat, time.time() - lastStat)))
moments.append(lattice.get_moments())
lastStat = time.time()
print("\nConcluded simulation.\n")
generate_moment_plots(lattice, moments)
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