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Adding an example of jaxdecomp implementation
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6644b35d71
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5 changed files with 166 additions and 192 deletions
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@ -3,19 +3,23 @@ from jax.experimental.maps import xmap
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import numpy as np
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import jax.numpy as jnp
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from functools import partial
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import jaxdecomp
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def fftk(shape, symmetric=False, dtype=np.float32, comms=None):
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def fftk(shape, symmetric=False, dtype=np.float32, sharding_info=None):
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""" Return k_vector given a shape (nc, nc, nc)
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"""
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k = []
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if comms is not None:
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nx = comms[0].Get_size()
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ix = comms[0].Get_rank()
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ny = comms[1].Get_size()
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iy = comms[1].Get_rank()
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shape = [shape[0]*nx, shape[1]*ny] + list(shape[2:])
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if sharding_info is not None:
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nx = sharding_info.pdims[1]
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ny = sharding_info.pdims[0]
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# nx = sharding_info[0].Get_size()
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# ix = sharding_info[0].Get_rank()
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# ny = sharding_info[1].Get_size()
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# iy = sharding_info[1].Get_rank()
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ix = sharding_info.rank
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iy = 0
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shape = sharding_info.global_shape
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for d in range(len(shape)):
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kd = np.fft.fftfreq(shape[d])
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@ -24,10 +28,10 @@ def fftk(shape, symmetric=False, dtype=np.float32, comms=None):
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if symmetric and d == len(shape) - 1:
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kd = kd[:shape[d] // 2 + 1]
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if (comms is not None) and d == 0:
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if (sharding_info is not None) and d == 0:
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kd = kd.reshape([nx, -1])[ix]
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if (comms is not None) and d == 1:
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if (sharding_info is not None) and d == 1:
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kd = kd.reshape([ny, -1])[iy]
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k.append(kd.astype(dtype))
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@ -42,10 +46,9 @@ def apply_gradient_laplace(kfield, kvec):
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kx, ky, kz = kvec
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kk = (kx**2 + ky**2 + kz**2)
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kernel = jnp.where(kk == 0, 1., 1./kk)
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return jnp.stack([kfield * kernel * 1j * 1 / 6.0 * (8 * jnp.sin(ky) - jnp.sin(2 * ky)),
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kfield * kernel * 1j * 1 / 6.0 *
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(8 * jnp.sin(kz) - jnp.sin(2 * kz)),
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kfield * kernel * 1j * 1 / 6.0 * (8 * jnp.sin(kx) - jnp.sin(2 * kx))], axis=-1)
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return jnp.stack([kfield * kernel * 1j * 1 / 6.0 * (8 * jnp.sin(kz) - jnp.sin(2 * kz)),
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kfield * kernel * 1j * 1 / 6.0 * (8 * jnp.sin(kx) - jnp.sin(2 * kx)),
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kfield * kernel * 1j * 1 / 6.0 * (8 * jnp.sin(ky) - jnp.sin(2 * ky))], axis=-1)
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def cic_compensation(kvec):
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184
jaxpm/ops.py
184
jaxpm/ops.py
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@ -2,155 +2,91 @@
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import jax
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import jax.numpy as jnp
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import mpi4jax
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import jaxdecomp
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from dataclasses import dataclass
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from typing import Tuple
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@dataclass
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class ShardingInfo:
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"""Class for keeping track of the distribution strategy"""
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global_shape: Tuple[int, int, int]
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pdims: Tuple[int, int]
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halo_extents: Tuple[int, int, int]
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rank: int = 0
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def fft3d(arr, comms=None):
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def fft3d(arr, sharding_info=None):
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""" Computes forward FFT, note that the output is transposed
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"""
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if comms is not None:
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shape = list(arr.shape)
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nx = comms[0].Get_size()
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ny = comms[1].Get_size()
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# First FFT along z
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arr = jnp.fft.fft(arr) # [x, y, z]
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# Perform single gpu or distributed transpose
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if comms == None:
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arr = arr.transpose([1, 2, 0])
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if sharding_info is None:
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arr = jnp.fft.fftn(arr).transpose([1, 2, 0])
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else:
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arr = arr.reshape(shape[:-1]+[nx, shape[-1] // nx])
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#arr = arr.transpose([2, 1, 3, 0]) # [y, z, x]
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arr = jnp.einsum('ij,xyjz->iyzx', jnp.eye(nx), arr) # TODO: remove this hack when we understand why transpose before alltoall doenst work
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arr, token = mpi4jax.alltoall(arr, comm=comms[0])
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arr = arr.transpose([1, 2, 0, 3]).reshape(shape) # Now [y, z, x]
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# Second FFT along x
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arr = jnp.fft.fft(arr)
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# Perform single gpu or distributed transpose
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if comms == None:
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arr = arr.transpose([1, 2, 0])
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else:
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arr = arr.reshape(shape[:-1]+[ny, shape[-1] // ny])
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#arr = arr.transpose([2, 1, 3, 0]) # [z, x, y]
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arr = jnp.einsum('ij,yzjx->izxy', jnp.eye(ny), arr) # TODO: remove this hack when we understand why transpose before alltoall doenst work
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arr, token = mpi4jax.alltoall(arr, comm=comms[1], token=token)
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arr = arr.transpose([1, 2, 0, 3]).reshape(shape) # Now [z, x, y]
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# Third FFT along y
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return jnp.fft.fft(arr)
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def ifft3d(arr, comms=None):
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""" Let's assume that the data is distributed accross x
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"""
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if comms is not None:
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shape = list(arr.shape)
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nx = comms[0].Get_size()
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ny = comms[1].Get_size()
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# First FFT along y
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arr = jnp.fft.ifft(arr) # Now [z, x, y]
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# Perform single gpu or distributed transpose
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if comms == None:
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arr = arr.transpose([0, 2, 1])
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else:
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arr = arr.reshape(shape[:-1]+[ny, shape[-1] // ny])
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# arr = arr.transpose([2, 0, 3, 1]) # Now [z, y, x]
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arr = jnp.einsum('ij,zxjy->izyx', jnp.eye(ny), arr) # TODO: remove this hack when we understand why transpose before alltoall doenst work
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arr, token = mpi4jax.alltoall(arr, comm=comms[1])
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arr = arr.transpose([1, 2, 0, 3]).reshape(shape) # Now [z,y,x]
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# Second FFT along x
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arr = jnp.fft.ifft(arr)
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# Perform single gpu or distributed transpose
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if comms == None:
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arr = arr.transpose([2, 1, 0])
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else:
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arr = arr.reshape(shape[:-1]+[nx, shape[-1] // nx])
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# arr = arr.transpose([2, 3, 1, 0]) # now [x, y, z]
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arr = jnp.einsum('ij,zyjx->ixyz', jnp.eye(nx), arr) # TODO: remove this hack when we understand why transpose before alltoall doenst work
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arr, token = mpi4jax.alltoall(arr, comm=comms[0], token=token)
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arr = arr.transpose([1, 2, 0, 3]).reshape(shape) # Now [x,y,z]
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# Third FFT along z
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return jnp.fft.ifft(arr)
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def halo_reduce(arr, halo_size, comms=None):
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if halo_size <= 0:
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return arr
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# Perform halo exchange along x
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rank_x = comms[0].Get_rank()
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size_x = comms[0].Get_size()
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margin = arr[-2*halo_size:]
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left, token = mpi4jax.sendrecv(margin, margin,
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(rank_x-1) % size_x,
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(rank_x+1) % size_x,
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comm=comms[0])
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margin = arr[:2*halo_size]
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right, token = mpi4jax.sendrecv(margin, margin,
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(rank_x+1) % size_x,
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(rank_x-1) % size_x,
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comm=comms[0], token=token)
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arr = arr.at[:2*halo_size].add(left)
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arr = arr.at[-2*halo_size:].add(right)
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# Perform halo exchange along y
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rank_y = comms[1].Get_rank()
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size_y = comms[1].Get_size()
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margin = arr[:, -2*halo_size:]
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left, token = mpi4jax.sendrecv(margin, margin,
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(rank_y-1) % size_y,
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(rank_y+1) % size_y,
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comm=comms[1], token=token)
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margin = arr[:, :2*halo_size]
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right, token = mpi4jax.sendrecv(margin, margin,
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(rank_y+1) % size_y,
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(rank_y-1) % size_y,
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comm=comms[1], token=token)
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arr = arr.at[:, :2*halo_size].add(left)
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arr = arr.at[:, -2*halo_size:].add(right)
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arr = jaxdecomp.pfft3d(arr,
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pdims=sharding_info.pdims,
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global_shape=sharding_info.global_shape)
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return arr
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def meshgrid3d(shape, comms=None):
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if comms is not None:
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nx = comms[0].Get_size()
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ny = comms[1].Get_size()
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def ifft3d(arr, sharding_info=None):
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if sharding_info is None:
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arr = jnp.fft.ifftn(arr.transpose([2, 0, 1]))
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else:
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arr = jaxdecomp.pifft3d(arr,
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pdims=sharding_info.pdims,
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global_shape=sharding_info.global_shape)
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return arr
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coords = [jnp.arange(shape[0]//nx),
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jnp.arange(shape[1]//ny)] + [jnp.arange(s) for s in shape[2:]]
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def halo_reduce(arr, sharding_info=None):
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if sharding_info is None:
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return arr
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halo_size = sharding_info.halo_extents[0]
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global_shape = sharding_info.global_shape
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arr = jaxdecomp.halo_exchange(arr,
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halo_extents=(halo_size//2, halo_size//2, 0),
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halo_periods=(True,True,True),
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pdims=sharding_info.pdims,
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global_shape=(global_shape[0]+2*halo_size,
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global_shape[1]+halo_size,
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global_shape[2]))
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# Apply correction along x
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arr = arr.at[halo_size:halo_size + halo_size//2].add(arr[ :halo_size//2])
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arr = arr.at[-halo_size - halo_size//2:-halo_size].add(arr[-halo_size//2:])
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# Apply correction along y
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arr = arr.at[:, halo_size:halo_size + halo_size//2].add(arr[:, :halo_size//2][:, :])
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arr = arr.at[:, -halo_size - halo_size//2:-halo_size].add(arr[:, -halo_size//2:][:, :])
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return arr
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def meshgrid3d(shape, sharding_info=None):
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if sharding_info is not None:
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coords = [jnp.arange(sharding_info.global_shape[0]//sharding_info.pdims[1]),
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jnp.arange(sharding_info.global_shape[1]//sharding_info.pdims[0]), jnp.arange(sharding_info.global_shape[2])]
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else:
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coords = [jnp.arange(s) for s in shape[2:]]
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return jnp.stack(jnp.meshgrid(*coords), axis=-1).reshape([-1, 3])
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def zeros(shape, comms=None):
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def zeros(shape, sharding_info=None):
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""" Initialize an array of given global shape
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partitionned if need be accross dimensions.
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"""
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if comms is None:
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if sharding_info is None:
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return jnp.zeros(shape)
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nx = comms[0].Get_size()
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ny = comms[1].Get_size()
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return jnp.zeros([shape[0]//nx, shape[1]//ny]+list(shape[2:]))
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return jnp.zeros([sharding_info.global_shape[0]//sharding_info.pdims[1], sharding_info.global_shape[1]//sharding_info.pdims[0]]+list(sharding_info.global_shape[2:]))
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def normal(key, shape, comms=None):
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def normal(key, shape, sharding_info=None):
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""" Generates a normal variable for the given
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global shape.
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"""
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if comms is None:
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if sharding_info is None:
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return jax.random.normal(key, shape)
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nx = comms[0].Get_size()
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ny = comms[1].Get_size()
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return jax.random.normal(key,
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[shape[0]//nx, shape[1]//ny]+list(shape[2:]))
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[sharding_info.global_shape[0]//sharding_info.pdims[1], sharding_info.global_shape[1]//sharding_info.pdims[0], sharding_info.global_shape[2]])
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@ -6,12 +6,12 @@ from jaxpm.ops import halo_reduce
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from jaxpm.kernels import fftk, cic_compensation
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def cic_paint(mesh, positions, halo_size=0, comms=None):
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def cic_paint(mesh, positions, halo_size=0, sharding_info=None):
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""" Paints positions onto mesh
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mesh: [nx, ny, nz]
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positions: [npart, 3]
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"""
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if comms is not None:
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if sharding_info is not None:
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# Add some padding for the halo exchange
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mesh = jnp.pad(mesh, [[halo_size, halo_size],
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[halo_size, halo_size],
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@ -40,26 +40,32 @@ def cic_paint(mesh, positions, halo_size=0, comms=None):
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kernel.reshape([-1, 8]),
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dnums)
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if comms == None:
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if sharding_info == None:
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return mesh
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else:
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mesh = halo_reduce(mesh, halo_size, comms)
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mesh = halo_reduce(mesh, sharding_info)
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return mesh[halo_size:-halo_size, halo_size:-halo_size]
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def cic_read(mesh, positions, halo_size=0, comms=None):
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def cic_read(mesh, positions, halo_size=0, sharding_info=None):
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""" Paints positions onto mesh
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mesh: [nx, ny, nz]
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positions: [npart, 3]
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"""
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if comms is not None:
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if sharding_info is not None:
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# Add some padding and perfom hao exchange to retrieve
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# neighboring regions
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mesh = jnp.pad(mesh, [[halo_size, halo_size],
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[halo_size, halo_size],
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[0, 0]])
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mesh = halo_reduce(mesh, halo_size, comms)
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# mesh = halo_reduce(mesh, sharding_info)
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import jaxdecomp
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mesh = jaxdecomp.halo_exchange(mesh,
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halo_extents=sharding_info.halo_extents,
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halo_periods=(True,True,True),
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pdims=sharding_info.pdims,
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global_shape=sharding_info.global_shape)
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positions += jnp.array([halo_size, halo_size, 0]).reshape([-1, 3])
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positions = jnp.expand_dims(positions, 1)
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30
jaxpm/pm.py
30
jaxpm/pm.py
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@ -10,32 +10,32 @@ from jaxpm.painting import cic_paint, cic_read
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from jaxpm.growth import growth_factor, growth_rate, dGfa
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def pm_forces(positions, mesh_shape=None, delta_k=None, halo_size=0, token=None, comms=None):
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def pm_forces(positions, mesh_shape=None, delta_k=None, halo_size=0, sharding_info=None):
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"""
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Computes gravitational forces on particles using a PM scheme
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"""
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if delta_k is None:
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delta = cic_paint(zeros(mesh_shape, comms=comms),
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delta = cic_paint(zeros(mesh_shape, sharding_info=sharding_info),
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positions,
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halo_size=halo_size, comms=comms)
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delta_k = fft3d(delta, comms=comms)
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halo_size=halo_size, sharding_info=sharding_info)
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delta_k = fft3d(delta, sharding_info=sharding_info)
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# Computes gravitational forces
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kvec = fftk(delta_k.shape, symmetric=False, comms=comms)
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kvec = fftk(delta_k.shape, symmetric=False, sharding_info=sharding_info)
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forces_k = apply_gradient_laplace(delta_k, kvec)
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# Interpolate forces at the position of particles
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return jnp.stack([cic_read(ifft3d(forces_k[..., i], comms=comms).real,
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positions, halo_size=halo_size, comms=comms)
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return jnp.stack([cic_read(ifft3d(forces_k[..., i], sharding_info=sharding_info).real,
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positions, halo_size=halo_size, sharding_info=sharding_info)
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for i in range(3)], axis=-1)
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def lpt(cosmo, positions, initial_conditions, a, halo_size=0, comms=None):
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def lpt(cosmo, positions, initial_conditions, a, halo_size=0, sharding_info=None):
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"""
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Computes first order LPT displacement
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"""
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initial_force = pm_forces(
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positions, delta_k=initial_conditions, halo_size=halo_size, comms=comms)
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positions, delta_k=initial_conditions, halo_size=halo_size, sharding_info=sharding_info)
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a = jnp.atleast_1d(a)
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dx = growth_factor(cosmo, a) * initial_force
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p = a**2 * growth_rate(cosmo, a) * \
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@ -45,21 +45,21 @@ def lpt(cosmo, positions, initial_conditions, a, halo_size=0, comms=None):
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return dx, p, f
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def linear_field(cosmo, mesh_shape, box_size, key, comms=None):
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def linear_field(cosmo, mesh_shape, box_size, key, sharding_info=None):
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"""
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Generate initial conditions in Fourier space.
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"""
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# Sample normal field
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field = normal(key, mesh_shape, comms=comms)
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field = normal(key, mesh_shape, sharding_info=sharding_info)
|
||||
|
||||
# Transform to Fourier space
|
||||
kfield = fft3d(field, comms=comms)
|
||||
kfield = fft3d(field, sharding_info=sharding_info)
|
||||
|
||||
# Rescaling k to physical units
|
||||
kvec = [k / box_size[i] * mesh_shape[i]
|
||||
for i, k in enumerate(fftk(kfield.shape,
|
||||
symmetric=False,
|
||||
comms=comms))]
|
||||
sharding_info=sharding_info))]
|
||||
|
||||
# Evaluating linear matter powerspectrum
|
||||
k = jnp.logspace(-4, 2, 256)
|
||||
|
@ -77,7 +77,7 @@ def linear_field(cosmo, mesh_shape, box_size, key, comms=None):
|
|||
return kfield
|
||||
|
||||
|
||||
def make_ode_fn(mesh_shape, halo_size=0, comms=None):
|
||||
def make_ode_fn(mesh_shape, halo_size=0, sharding_info=None):
|
||||
|
||||
def nbody_ode(state, a, cosmo):
|
||||
"""
|
||||
|
@ -86,7 +86,7 @@ def make_ode_fn(mesh_shape, halo_size=0, comms=None):
|
|||
pos, vel = state
|
||||
|
||||
forces = pm_forces(pos, mesh_shape=mesh_shape,
|
||||
halo_size=halo_size, comms=comms) * 1.5 * cosmo.Omega_m
|
||||
halo_size=halo_size, sharding_info=sharding_info) * 1.5 * cosmo.Omega_m
|
||||
|
||||
# Computes the update of position (drift)
|
||||
dpos = 1. / (a**3 * jnp.sqrt(jc.background.Esqr(cosmo, a))) * vel
|
||||
|
|
Loading…
Add table
Add a link
Reference in a new issue