box = ((0.0, 0.0, 0.0), (boxsize, boxsize, boxsize))
nx = ds.domain_dimensions[0]
## set voxelization options
order = 1
tol = 1000
subgrid = (subgridsize, subgridsize, subgridsize)
window = box
fields = {'m': None}
## chunk through Lagrangian patches
mtot = 0.0
tstart = time.time()
for pos, vel, mass, block, nblocks in psi.elementBlocksFromGrid(pos, vel, order=order, periodic=True):
## make periodic and voxelize it
psi.voxelize(fields, pos, vel, mass, tol=tol, window=window, \
grid=subgrid, periodic=True, box=box)
## bookkeeping
mtot += np.sum(mass)
tend = time.time()
sys.stdout.write("\rVoxelized block %d of %d. Time = %.1f s" % (block, nblocks, tend-tstart))
sys.stdout.flush()
print '\nGlobal error = %.10e' % np.abs(np.sum(fields['m'])/mtot-1.0)
# save density data to file
f = tables.open_file("density%04d_64.h5" % i, mode = 'w')
f.create_array(f.root, "density", fields['m'])
f.close()
i += 1
