skais_mapper.illustris.util

Illustris simulation snapshot utilities.

Adapted from: https://github.com/illustristng/illustris_python

Classes:

Name	Description
IllustrisH5File	Represents an Illustris HDF5 file. Wrapper for the class.

Functions:

Name	Description
pidx_from_ptype	Mapping common names to indices of particle types.
ptype_from_pidx	Mapping indices to names of particle types.

IllustrisH5File

IllustrisH5File(
    base_path: str | Path,
    snapshot: int,
    partition: int = 0,
    path_func: Callable | None = None,
    mode: str = "r",
    driver: str | None = None,
    cache_size: int | float | str = "2G",
    **kwargs,
)

Bases: h5py.File

Represents an Illustris HDF5 file. Wrapper for the class.

Initialize a IllustrisH5File instance.

Parameters:

Name	Type	Description	Default
base_path	str | Path	Base path to the Illustris(TNG) snapshots.	required
snapshot	int	Snapshot ID {0-99}.	required
partition	int	Subfile partition ID {0-600+}.	0
path_func	Callable | None	A function fetching the filename of the HDF5 file. The function should accept , , as arguments.	None
mode	str	'r' Readonly, file must exist (default) 'r+' Read/write, file must exist 'w' Create file, truncate if exists 'w-' or 'x' Create file, fail if exists 'a' Read/write if exists, create otherwise.	'r'
driver	str | None	Name of the driver to use; valid values are None (default), 'core', 'sec2', 'direct', 'stdio', 'mpio', 'ros3'.	None
cache_size	int | float | str	Chunk cache size in bytes or passed as string.	'2G'
**kwargs		More keyword arguments	{}

Source code in skais_mapper/illustris/util.py

def __init__(
    self,
    base_path: str | Path,
    snapshot: int,
    partition: int = 0,
    path_func: Callable | None = None,
    mode: str = "r",
    driver: str | None = None,
    cache_size: int | float | str = "2G",
    **kwargs,
):
    """Initialize a IllustrisH5File instance.

    Args:
        base_path: Base path to the Illustris(TNG) snapshots.
        snapshot: Snapshot ID {0-99}.
        partition: Subfile partition ID {0-600+}.
        path_func:
            A function fetching the filename of the HDF5 file. The function
            should accept <base_path>, <snapshot>, <partition> as arguments.
        mode:
            'r'          Readonly, file must exist (default)
            'r+'         Read/write, file must exist
            'w'          Create file, truncate if exists
            'w-' or 'x'  Create file, fail if exists
            'a'          Read/write if exists, create otherwise.
        driver: Name of the driver to use; valid values are
            None (default), 'core', 'sec2', 'direct', 'stdio', 'mpio', 'ros3'.
        cache_size: Chunk cache size in bytes or passed as string.
        **kwargs: More keyword arguments
    """
    self.exists = True
    self.chunk_cache_size = nbytes(cache_size)
    kwargs.setdefault("rdcc_nbytes", int(self.chunk_cache_size))
    kwargs.setdefault("rdcc_w0", 1.0)
    if os.path.exists(self.filename):
        super().__init__(self.filename, mode=mode, driver=driver, **kwargs)
    else:
        self.exists = False

pidx_from_ptype

pidx_from_ptype(ptype: int | str) -> int

Mapping common names to indices of particle types.

Parameters:

Name	Type	Description	Default
ptype	int | str	particle type description string	required

Returns:

Type	Description
int	(int) particle type index 0 -> gas particles 1 -> dark-matter particles 2 -> lowres dark-matter / stellar disc particles (in zoom simulations) 3 -> tracer / stellar buldge particles 4 -> star / wind / stellar particles 5 -> blackhole / sink particles

Raises:

Type	Description
ValueError	If the name doesn't match any particle type.

Source code in skais_mapper/illustris/util.py

def pidx_from_ptype(ptype: int | str) -> int:
    """Mapping common names to indices of particle types.

    Args:
        ptype: particle type description string

    Returns:
        (int) particle type index
          0 -> gas particles
          1 -> dark-matter particles
          2 -> lowres dark-matter / stellar disc particles (in zoom simulations)
          3 -> tracer / stellar buldge particles
          4 -> star / wind / stellar particles
          5 -> blackhole / sink particles

    Raises:
        (ValueError): If the name doesn't match any particle type.
    """
    if str(ptype).isdigit():
        return int(ptype)
    if str(ptype).lower() in ["gas", "cells"]:
        return 0
    if str(ptype).lower() in ["dm", "darkmatter"]:
        return 1
    if str(ptype).lower() in ["dmlowres"]:
        return 2  # only zoom simulations, not present in full periodic boxes
    if str(ptype).lower() in ["tracer", "tracers", "tracermc", "trmc"]:
        return 3
    if str(ptype).lower() in ["star", "stars", "stellar"]:
        return 4  # only those with GFM_StellarFormationTime > 0
    if str(ptype).lower() in ["wind"]:
        return 4  # only those with GFM_StellarFormationTime < 0
    if str(ptype).lower() in ["bh", "bhs", "blackhole", "blackholes"]:
        return 5
    raise ValueError(f"Unknown particle type name {ptype}.")

ptype_from_pidx

ptype_from_pidx(pidx: int | str) -> str

Mapping indices to names of particle types.

Parameters:

Name	Type	Description	Default
pidx	int | str	particle type index	required

Returns:

Type	Description
str	(int) particle type index gas particles -> 0 dark-matter particles -> 1 lowres dark-matter / stellar disc particles (in zoom simulations) -> 2 tracer / stellar buldge particles -> 3 star / wind / stellar particles -> 4 blackhole / sink particles -> 5

Raises:

Type	Description
ValueError	If the index is not

Source code in skais_mapper/illustris/util.py

def ptype_from_pidx(pidx: int | str) -> str:
    """Mapping indices to names of particle types.

    Args:
        pidx: particle type index

    Returns:
        (int) particle type index
          gas particles -> 0
          dark-matter particles -> 1
          lowres dark-matter / stellar disc particles (in zoom simulations) -> 2
          tracer / stellar buldge particles -> 3
          star / wind / stellar particles -> 4
          blackhole / sink particles -> 5

    Raises:
        (ValueError): If the index is not
    """
    if isinstance(pidx, str):
        return pidx
    if pidx == 0:
        return "gas"
    if pidx == 1:
        return "dm"
    if pidx == 2:
        return "dmlowres"  # only zoom simulations, not present in full periodic boxes
    if pidx == 3:
        return "tracer"
    if pidx == 4:
        return "star"  # only those with GFM_StellarFormationTime > 0
    if pidx == 5:
        return "bh"
    raise ValueError(f"Unknown particle type name {pidx}.")