def load_amr_grids(
grid_data,
domain_dimensions,
bbox=None,
sim_time=0.0,
length_unit=None,
mass_unit=None,
time_unit=None,
velocity_unit=None,
magnetic_unit=None,
periodicity=(True, True, True),
geometry="cartesian",
refine_by=2,
unit_system="cgs",
):
r"""Load a set of grids of data into yt as a
:class:`~yt.frontends.stream.data_structures.StreamHandler`.
This should allow a sequence of grids of varying resolution of data to be
loaded directly into yt and analyzed as would any others. This comes with
several caveats:
* Units will be incorrect unless the unit system is explicitly specified.
* Some functions may behave oddly, and parallelism will be
disappointing or non-existent in most cases.
* Particles may be difficult to integrate.
* No consistency checks are performed on the index
Parameters
----------
grid_data : list of dicts
This is a list of dicts. Each dict must have entries "left_edge",
"right_edge", "dimensions", "level", and then any remaining entries are
assumed to be fields. Field entries must map to an NDArray. The grid_data
may also include a particle count. If no particle count is supplied, the
dataset is understood to contain no particles. The grid_data will be
modified in place and can't be assumed to be static.
domain_dimensions : array_like
This is the domain dimensions of the grid
length_unit : string or float
Unit to use for lengths. Defaults to unitless. If set to be a string, the bbox
dimensions are assumed to be in the corresponding units. If set to a float, the
value is a assumed to be the conversion from bbox dimensions to centimeters.
mass_unit : string or float
Unit to use for masses. Defaults to unitless.
time_unit : string or float
Unit to use for times. Defaults to unitless.
velocity_unit : string or float
Unit to use for velocities. Defaults to unitless.
magnetic_unit : string or float
Unit to use for magnetic fields. Defaults to unitless.
bbox : array_like (xdim:zdim, LE:RE), optional
Size of computational domain in units specified by length_unit.
Defaults to a cubic unit-length domain.
sim_time : float, optional
The simulation time in seconds
periodicity : tuple of booleans
Determines whether the data will be treated as periodic along
each axis
geometry : string or tuple
"cartesian", "cylindrical", "polar", "spherical", "geographic" or
"spectral_cube". Optionally, a tuple can be provided to specify the
axis ordering -- for instance, to specify that the axis ordering should
be z, x, y, this would be: ("cartesian", ("z", "x", "y")). The same
can be done for other coordinates, for instance:
("spherical", ("theta", "phi", "r")).
refine_by : integer or list/array of integers.
Specifies the refinement ratio between levels. Defaults to 2. This
can be an array, in which case it specifies for each dimension. For
instance, this can be used to say that some datasets have refinement of
1 in one dimension, indicating that they span the full range in that
dimension.
Examples
--------
>>> grid_data = [
... dict(left_edge = [0.0, 0.0, 0.0],
... right_edge = [1.0, 1.0, 1.],
... level = 0,
... dimensions = [32, 32, 32],
... number_of_particles = 0),
... dict(left_edge = [0.25, 0.25, 0.25],
... right_edge = [0.75, 0.75, 0.75],
... level = 1,
... dimensions = [32, 32, 32],
... number_of_particles = 0)
... ]
...
>>> for g in grid_data:
... g["density"] = (np.random.random(g["dimensions"])*2**g["level"], "g/cm**3")
...
>>> ds = load_amr_grids(grid_data, [32, 32, 32], length_unit=1.0)
"""
from yt.frontends.stream.data_structures import (
StreamDataset,
StreamDictFieldHandler,
StreamHandler,
)
from yt.frontends.stream.definitions import process_data, set_particle_types
domain_dimensions = np.array(domain_dimensions)
ngrids = len(grid_data)
if bbox is None:
bbox = np.array([[0.0, 1.0], [0.0, 1.0], [0.0, 1.0]], "float64")
domain_left_edge = np.array(bbox[:, 0], "float64")
domain_right_edge = np.array(bbox[:, 1], "float64")
grid_levels = np.zeros((ngrids, 1), dtype="int32")
grid_left_edges = np.zeros((ngrids, 3), dtype="float64")
grid_right_edges = np.zeros((ngrids, 3), dtype="float64")
grid_dimensions = np.zeros((ngrids, 3), dtype="int32")
number_of_particles = np.zeros((ngrids, 1), dtype="int64")
parent_ids = np.zeros(ngrids, dtype="int64") - 1
sfh = StreamDictFieldHandler()
for i, g in enumerate(grid_data):
grid_left_edges[i, :] = g.pop("left_edge")
grid_right_edges[i, :] = g.pop("right_edge")
grid_dimensions[i, :] = g.pop("dimensions")
grid_levels[i, :] = g.pop("level")
# If someone included this throw it away--old API
if "number_of_particles" in g:
issue_deprecation_warning(
"It is no longer necessary to include "
"the number of particles in the data "
"dict. The number of particles is "
"determined from the sizes of the "
"particle fields.",
since="4.0.0",
removal="4.1.0",
)
g.pop("number_of_particles")
field_units, data, n_particles = process_data(
g, grid_dims=tuple(grid_dimensions[i, :])
)
number_of_particles[i, :] = n_particles
sfh[i] = data
# We now reconstruct our parent ids, so that our particle assignment can
# proceed.
mask = np.empty(ngrids, dtype="int32")
for gi in range(ngrids):
get_box_grids_level(
grid_left_edges[gi, :],
grid_right_edges[gi, :],
grid_levels[gi] + 1,
grid_left_edges,
grid_right_edges,
grid_levels,
mask,
)
ids = np.where(mask.astype("bool"))
for ci in ids:
parent_ids[ci] = gi
# Check if the grid structure is properly aligned (bug #1295)
for lvl in range(grid_levels.min() + 1, grid_levels.max() + 1):
idx = grid_levels.flatten() == lvl
dims = domain_dimensions * refine_by ** (lvl - 1)
for iax, ax in enumerate("xyz"):
cell_edges = np.linspace(
domain_left_edge[iax], domain_right_edge[iax], dims[iax], endpoint=False
)
if set(grid_left_edges[idx, iax]) - set(cell_edges):
raise YTIllDefinedAMR(lvl, ax)
if length_unit is None:
length_unit = "code_length"
if mass_unit is None:
mass_unit = "code_mass"
if time_unit is None:
time_unit = "code_time"
if velocity_unit is None:
velocity_unit = "code_velocity"
if magnetic_unit is None:
magnetic_unit = "code_magnetic"
particle_types = {}
for grid in sfh.values():
particle_types.update(set_particle_types(grid))
handler = StreamHandler(
grid_left_edges,
grid_right_edges,
grid_dimensions,
grid_levels,
parent_ids,
number_of_particles,
np.zeros(ngrids).reshape((ngrids, 1)),
sfh,
field_units,
(length_unit, mass_unit, time_unit, velocity_unit, magnetic_unit),
particle_types=particle_types,
periodicity=periodicity,
)
handler.name = "AMRGridData"
handler.domain_left_edge = domain_left_edge
handler.domain_right_edge = domain_right_edge
handler.refine_by = refine_by
if np.all(domain_dimensions[1:] == 1):
dimensionality = 1
elif domain_dimensions[2] == 1:
dimensionality = 2
else:
dimensionality = 3
handler.dimensionality = dimensionality
handler.domain_dimensions = domain_dimensions
handler.simulation_time = sim_time
handler.cosmology_simulation = 0
sds = StreamDataset(handler, geometry=geometry, unit_system=unit_system)
return sds
def load_uniform_grid(
data,
domain_dimensions,
length_unit=None,
bbox=None,
nprocs=1,
sim_time=0.0,
mass_unit=None,
time_unit=None,
velocity_unit=None,
magnetic_unit=None,
periodicity=(True, True, True),
geometry="cartesian",
unit_system="cgs",
):
r"""Load a uniform grid of data into yt as a
:class:`~yt.frontends.stream.data_structures.StreamHandler`.
This should allow a uniform grid of data to be loaded directly into yt and
analyzed as would any others. This comes with several caveats:
* Units will be incorrect unless the unit system is explicitly
specified.
* Some functions may behave oddly, and parallelism will be
disappointing or non-existent in most cases.
* Particles may be difficult to integrate.
Particle fields are detected as one-dimensional fields.
Parameters
----------
data : dict
This is a dict of numpy arrays or (numpy array, unit spec) tuples.
The keys are the field names.
domain_dimensions : array_like
This is the domain dimensions of the grid
length_unit : string
Unit to use for lengths. Defaults to unitless.
bbox : array_like (xdim:zdim, LE:RE), optional
Size of computational domain in units specified by length_unit.
Defaults to a cubic unit-length domain.
nprocs: integer, optional
If greater than 1, will create this number of subarrays out of data
sim_time : float, optional
The simulation time in seconds
mass_unit : string
Unit to use for masses. Defaults to unitless.
time_unit : string
Unit to use for times. Defaults to unitless.
velocity_unit : string
Unit to use for velocities. Defaults to unitless.
magnetic_unit : string
Unit to use for magnetic fields. Defaults to unitless.
periodicity : tuple of booleans
Determines whether the data will be treated as periodic along
each axis
geometry : string or tuple
"cartesian", "cylindrical", "polar", "spherical", "geographic" or
"spectral_cube". Optionally, a tuple can be provided to specify the
axis ordering -- for instance, to specify that the axis ordering should
be z, x, y, this would be: ("cartesian", ("z", "x", "y")). The same
can be done for other coordinates, for instance:
("spherical", ("theta", "phi", "r")).
Examples
--------
>>> np.random.seed(int(0x4D3D3D3))
>>> bbox = np.array([[0., 1.0], [-1.5, 1.5], [1.0, 2.5]])
>>> arr = np.random.random((128, 128, 128))
>>> data = dict(density=arr)
>>> ds = load_uniform_grid(data, arr.shape, length_unit='cm',
... bbox=bbox, nprocs=12)
>>> dd = ds.all_data()
>>> dd['density']
unyt_array([0.76017901, 0.96855994, 0.49205428, ..., 0.78798258,
0.97569432, 0.99453904], 'g/cm**3')
"""
from yt.frontends.stream.data_structures import (
StreamDataset,
StreamDictFieldHandler,
StreamHandler,
)
from yt.frontends.stream.definitions import (
assign_particle_data,
process_data,
set_particle_types,
)
domain_dimensions = np.array(domain_dimensions)
if bbox is None:
bbox = np.array([[0.0, 1.0], [0.0, 1.0], [0.0, 1.0]], "float64")
domain_left_edge = np.array(bbox[:, 0], "float64")
domain_right_edge = np.array(bbox[:, 1], "float64")
grid_levels = np.zeros(nprocs, dtype="int32").reshape((nprocs, 1))
# If someone included this throw it away--old API
if "number_of_particles" in data:
issue_deprecation_warning(
"It is no longer necessary to include "
"the number of particles in the data "
"dict. The number of particles is "
"determined from the sizes of the "
"particle fields.",
since="4.0.0",
removal="4.1.0",
)
data.pop("number_of_particles")
# First we fix our field names, apply units to data
# and check for consistency of field shapes
field_units, data, number_of_particles = process_data(
data, grid_dims=tuple(domain_dimensions)
)
sfh = StreamDictFieldHandler()
if number_of_particles > 0:
particle_types = set_particle_types(data)
# Used much further below.
pdata = {"number_of_particles": number_of_particles}
for key in list(data.keys()):
if len(data[key].shape) == 1 or key[0] == "io":
if not isinstance(key, tuple):
field = ("io", key)
mylog.debug("Reassigning '%s' to '%s'", key, field)
else:
field = key
sfh._additional_fields += (field,)
pdata[field] = data.pop(key)
else:
particle_types = {}
if nprocs > 1:
temp = {}
new_data = {}
for key in data.keys():
psize = get_psize(np.array(data[key].shape), nprocs)
grid_left_edges, grid_right_edges, shapes, slices = decompose_array(
data[key].shape, psize, bbox
)
grid_dimensions = np.array([shape for shape in shapes], dtype="int32")
temp[key] = [data[key][slice] for slice in slices]
for gid in range(nprocs):
new_data[gid] = {}
for key in temp.keys():
new_data[gid].update({key: temp[key][gid]})
sfh.update(new_data)
del new_data, temp
else:
sfh.update({0: data})
grid_left_edges = domain_left_edge
grid_right_edges = domain_right_edge
grid_dimensions = domain_dimensions.reshape(nprocs, 3).astype("int32")
if length_unit is None:
length_unit = "code_length"
if mass_unit is None:
mass_unit = "code_mass"
if time_unit is None:
time_unit = "code_time"
if velocity_unit is None:
velocity_unit = "code_velocity"
if magnetic_unit is None:
magnetic_unit = "code_magnetic"
handler = StreamHandler(
grid_left_edges,
grid_right_edges,
grid_dimensions,
grid_levels,
-np.ones(nprocs, dtype="int64"),
np.zeros(nprocs, dtype="int64").reshape(nprocs, 1), # particle count
np.zeros(nprocs).reshape((nprocs, 1)),
sfh,
field_units,
(length_unit, mass_unit, time_unit, velocity_unit, magnetic_unit),
particle_types=particle_types,
periodicity=periodicity,
)
handler.name = "UniformGridData"
handler.domain_left_edge = domain_left_edge
handler.domain_right_edge = domain_right_edge
handler.refine_by = 2
if np.all(domain_dimensions[1:] == 1):
dimensionality = 1
elif domain_dimensions[2] == 1:
dimensionality = 2
else:
dimensionality = 3
handler.dimensionality = dimensionality
handler.domain_dimensions = domain_dimensions
handler.simulation_time = sim_time
handler.cosmology_simulation = 0
sds = StreamDataset(handler, geometry=geometry, unit_system=unit_system)
# Now figure out where the particles go
if number_of_particles > 0:
# This will update the stream handler too
assign_particle_data(sds, pdata, bbox)
return sds