cosmotool/python/cosmotool/smooth.py

110 lines
3.1 KiB
Python

from .config import install_prefix
import subprocess
import os
try:
from tempfile import TemporaryDirectory
except:
from backports.tempfile import TemporaryDirectory
import h5py as h5
import numpy as np
import weakref
def smooth_particle_density(
position,
velocities=None,
radius=1e6,
boxsize=None,
resolution=128,
center=None, tmpprefix=None ):
"""Use adaptive smoothing to produce density and momentum fields.
The algorithm is originally described in [1].
Parameters:
position : numpy array NxQ
the particle positions
if Q==3, only positions. Q==6 means full space phase
velocities : Optional numpy array Nx3.
It is only optional if the above Q is 6.
radius : float
Maximum radius to which we need to compute fields
boxsize : float
Size of the box for the generated fields
resolution : int
Resolution of the output boxes
center : list of 3 floats
Center of the new box. It depends on the convention
for particles. If those are between [0, L], then [0,0,0]
is correct. If those are [-L/2,L/2] then you should set
[L/2,L/2,L/2].
tmpprefix : string
prefix of the temporary directory that will be used.
It needs to have a lot of space available. By default
'/tmp/ will be typically used.
Returns
-------
dictionnary
The dict has two entries: 'rho' for the density, and 'p' for the momenta.
Once the dictionary is garbage collected all temporary files and directories
will be cleared automatically.
Raises
------
ValueError
if arguments are invalid
.. [1] S. Colombi, M. Chodorowski,
"Cosmic velocity-gravity in redshift space", MNRAS, 2007, 375, 1
"""
if len(position.shape) != 2:
raise ValueError("Invalid position array shape")
if velocities is None:
if position.shape[1] != 6:
raise ValueError("Position must be phase space if no velocities are given")
if boxsize is None:
raise ValueError("Need a boxsize")
cx,cy,cz=center
tmpdir = TemporaryDirectory(prefix=tmpprefix)
h5_file = os.path.join(tmpdir.name, 'particles.h5')
with h5.File(h5_file, mode="w") as f:
data = f.create_dataset('particles', shape=(position.shape[0],7), dtype=np.float32)
data[:,:3] = position[:,:3]
if velocities is not None:
data[:,3:6] = velocities[:,:3]
else:
data[:,3:6] = position[:,3:]
data[:,6] = 1
ret = \
subprocess.run([
os.path.join(install_prefix,'bin','simple3DFilter'),
h5_file,
str(radius),
str(boxsize),
str(resolution),
str(cx), str(cy), str(cz)
], cwd=tmpdir.name)
f0 = h5.File(os.path.join(tmpdir.name,'fields.h5'), mode="r")
def cleanup_f0():
f0.close()
tmpdir.cleanup()
class Dict(dict):
pass
t = Dict(rho=f0['density'], p=[f0['p0'], f0['p1'], f0['p2']])
t._tmpdir_=tmpdir
weakref.finalize(t, cleanup_f0)
return t