Data Acquisition Functions

get_age(snapshot::String, time::Unitful.Quantity; <keyword arguments>)::Dict{String,Any}

Get the ages of the stars at a specific time step.

Arguments

• snapshot::String: Path to a given snapshot.

• time::Unitful.Quantity: Clock time of snapshot, with units. All available time units in Unitful.jl and UnitfulAstro.jl can be used.

• sim_cosmo::Int64 = 0: Value of the GADGET variable ComovingIntegrationOn:

  • 0 ⟶ Newtonian simulation (static universe).
  • 1 ⟶ Cosmological simulation (expanding universe).

• snap_0::String = "": Path to the fist snapshot. Only relevant for cosmological simulations (sim_cosmo = 1).

• filter_function::Function = pass_all: A function with the signature:

  foo(snap_file::String, type::String)::Vector{Int64}

  See the function pass_all for an example. By default, no particles are filtered.

Returns

• A dictionary with two entries.
  • "ages" ⟹ The ages of the stars.
  • "unit" ⟹ The unit of time used.

get_birth_place(
    snap_index::Int64,
    snap_files::Vector{String},
    time_stamps::Vector{Float64},
    stamps_unit::Unitful.FreeUnits; 
    <keyword arguments>
)::Dict{String, Any}

Get the birth location of the stars in a given snapshot.

Arguments

• snap_index::Int64: Index in snap_files of the snapshot whose stars will be located.

• snap_files::Vector{String}: Output of the function get_snapshot_path corresponding to the key "snap_files", containing an Array with the paths to the snapshots.

• time_stamps::Vector{Float64}: Clock time of every snapshot in snap_files.

• stamps_unit::Unitful.FreeUnits: Unit of time of the time_stamps.

• sim_cosmo::Int64 = 0: Value of the GADGET variable ComovingIntegrationOn:

  • 0 ⟶ Newtonian simulation (static universe).
  • 1 ⟶ Cosmological simulation (expanding universe).

• filter_function::Function = pass_all: A function with the signature:

  foo(snap_file::String, type::String)::Vector{Int64}

  See the function pass_all for an example. By default, no particles are filtered.

• length_unit::Unitful.FreeUnits = UnitfulAstro.kpc: Unit of length to be used in the output, all available length units in Unitful.jl and UnitfulAstro.jl can be used.

Returns

• A 2 dimensional arrays with the positions of the stars. Each row is a star and each column corresponds to coordinates x, y and z respectively.

get_cpu_txt(
    source_path::String, 
    target::String; 
    <keyword arguments>
)::Dict{String, Matrix{Float64}}

Get the data from the cpu.txt file.

For the row in target a matrix with all the CPU usage data (as percentages of total CPU time) is returned.

Arguments

• source_path::String: Path to the directory containing the cpu.txt file.
• target::String: Target process.
• step::Int64 = 1: Step used to traverse the CPU cycles, i.e. one every step cycles is returned.

Returns

• A dictionary with one entry.
  • process ⟹ Matrix with CPU cycles as its first column, and CPU usage (in percentage) as its second column.

get_cpu_txt(
    source_path::String, 
    targets::Vector{String}; 
    <keyword arguments>
)::Dict{String, Matrix{Float64}}

Get the data from the cpu.txt file.

For each target row in targets a matrix with all the CPU usage data (as percentages of total CPU time) is returned.

Arguments

• source_path::String: Path to the directory containing the cpu.txt file.
• targets::Vector{String}: Target processes.
• step::Int64 = 1: Step used to traverse the CPU cycles, i.e. one every step cycles is returned.

Returns

• A dictionary with as many entries as strings in targets.
  • process ⟹ Matrix with CPU cycles as its first column, and CPU usage (in percentage) as its second column.

get_density(snapshot::String; <keyword arguments>)::Dict{String,Any}

Get the densities of the gas particles at a specific time step.

Arguments

• snapshot::String: Path to the snapshot file.

• sim_cosmo::Int64 = 0: Value of the GADGET variable ComovingIntegrationOn:

  • 0 ⟶ Newtonian simulation (static universe).
  • 1 ⟶ Cosmological simulation (expanding universe).

• filter_function::Function = pass_all: A function with the signature:

  foo(snap_file::String, type::String)::Vector{Int64}

  See the function pass_all for an example. By default, no particles are filtered.

• density_unit::Unitful.FreeUnits = UnitfulAstro.Msun / UnitfulAstro.kpc^3: Unit of density to be used in the output, all available density units in Unitful.jl and UnitfulAstro.jl can be used.

Returns

• A dictionary with two entries.
  • "density" ⟹ Densities of the gas particles.
  • "unit" ⟹ The unit of density used, i.e. is a pass-through of density_unit.

get_fatom(snapshot::String; <keyword arguments>)::Vector{Float64}

Get the fraction of atomic gas of each particle at a specific time step.

Arguments

• snapshot::String: Path to a given snapshot.

• sim_cosmo::Int64 = 0: Value of the GADGET variable ComovingIntegrationOn:

  • 0 ⟶ Newtonian simulation (static universe).
  • 1 ⟶ Cosmological simulation (expanding universe).

• filter_function::Function = pass_all: A function with the signature:

  foo(snap_file::String, type::String)::Vector{Int64}

  See the function pass_all for an example. By default, no particles are filtered.

Returns

• Vector with fraction of atomic gas of each particle

get_fmol(snapshot::String; <keyword arguments>)::Vector{Float64}

Get the fraction of molecular gas of each particle at a specific time step.

Arguments

• snapshot::String: Path to a given snapshot.

• sim_cosmo::Int64 = 0: Value of the GADGET variable ComovingIntegrationOn:

  • 0 ⟶ Newtonian simulation (static universe).
  • 1 ⟶ Cosmological simulation (expanding universe).

• filter_function::Function = pass_all: A function with the signature:

  foo(snap_file::String, type::String)::Vector{Int64}

  See the function pass_all for an example. By default, no particles are filtered.

Returns

• Vector with fraction of molecular gas of each particle

get_hsml(snapshot::String; <keyword arguments>)::Dict{String,Any}

Get the smoothing lengths of the gas particles at a specific time step.

Arguments

• snapshot::String: Path to a given snapshot.

• sim_cosmo::Int64 = 0: Value of the GADGET variable ComovingIntegrationOn:

  • 0 ⟶ Newtonian simulation (static universe).
  • 1 ⟶ Cosmological simulation (expanding universe).

• filter_function::Function = pass_all: A function with the signature:

  foo(snap_file::String, type::String)::Vector{Int64}

  See the function pass_all for an example. By default, no particles are filtered.

• length_unit::Unitful.FreeUnits = UnitfulAstro.kpc: Unit of length to be used in the output, all available length units in Unitful.jl and UnitfulAstro.jl can be used.

Returns

• A dictionary with two entries.
  • "hsml" ⟹ Smoothing lengths of the gas particles.
  • "unit" ⟹ The unit of length used, i.e. is a pass-through of length_unit.

get_mass(snapshot::String, type::String; <keyword arguments>)::Dict{String,Any}

Get the mass of all the particles at a specific time step.

Arguments

• snapshot::String: Path to a given snapshot.

• type::String: Particle type.

  • "gas" ⟶ Gas particle.
  • "dark_matter" ⟶ Dark matter particle.
  • "stars" ⟶ Star particle.

• sim_cosmo::Int64 = 0: Value of the GADGET variable ComovingIntegrationOn:

  • 0 ⟶ Newtonian simulation (static universe).
  • 1 ⟶ Cosmological simulation (expanding universe).

• filter_function::Function = pass_all: A function with the signature:

  foo(snap_file::String, type::String)::Vector{Int64}

  See the function pass_all for an example. By default, no particles are filtered.

• mass_unit::Unitful.FreeUnits = UnitfulAstro.Msun: Unit of mass to be used in the output, all available mass units in Unitful.jl and UnitfulAstro.jl can be used.

Returns

• A dictionary with three entries.
  • "mass" ⟹ Masses of the particles.
  • "unit" ⟹ The unit of mass used, i.e. is a pass-through of mass_unit.
  • "type" ⟹ Particle type, i.e. is a pass-through of type.

get_metal_mass(snapshot::String, type::String; <keyword arguments>)::Dict{String,Any}

Get the mass of several elements within each particle at a specific time step.

Arguments

• snapshot::String: Path to a given snapshot.

• type::String: Particle type.

  • "gas" ⟶ Gas particle.
  • "stars" ⟶ Star particle.

• sim_cosmo::Int64 = 0: Value of the GADGET variable ComovingIntegrationOn:

  • 0 ⟶ Newtonian simulation (static universe).
  • 1 ⟶ Cosmological simulation (expanding universe).

• filter_function::Function = pass_all: A function with the signature:

  foo(snap_file::String, type::String)::Vector{Int64}

  See the function pass_all for an example. By default, no particles are filtered.

• mass_unit::Unitful.FreeUnits = UnitfulAstro.Msun: Unit of mass to be used in the output, all available mass units in Unitful.jl and UnitfulAstro.jl can be used.

Returns

• A dictionary with two entries.
  • "Z" ⟹ Matrix where each row is an element, and each column a particle.
    • 01: He (Helium)

* 02: C (Carbon)
* 03: Mg (Magnesium)
* 04: 0 (Oxygen)
* 05: Fe (Iron)
* 06: Si (Silicon)
* 07: H (Hydrogen)
* 08: N (Nitrogen)
* 09: Ne (Neon)
* 10: S (Sulfur)
* 11: Ca (Calcium)
* 12: Zn (Zinc)

• "unit" ⟹ The unit of mass used, i.e. is a pass-through of mass_unit.
• "type" ⟹ Particle type, i.e. is a pass-through of type.

get_metallicity(snapshot::String, type::String; <keyword arguments>)::Dict{String,Any}

Get the metallicity of the particles at a specific time step. With metallicity define as the total mass of all elements except Hydrogen and Helium.

Arguments

• snapshot::String: Path to a given snapshot.

• type::String: Particle type.

  • "gas" ⟶ Gas particle.
  • "stars" ⟶ Star particle.

• sim_cosmo::Int64 = 0: Value of the GADGET variable ComovingIntegrationOn:

  • 0 ⟶ Newtonian simulation (static universe).
  • 1 ⟶ Cosmological simulation (expanding universe).

• filter_function::Function = pass_all: A function with the signature:

  foo(snap_file::String, type::String)::Vector{Int64}

  See the function pass_all for an example. By default, no particles are filtered.

• mass_unit::Unitful.FreeUnits = UnitfulAstro.Msun: Unit of mass to be used in the output, all available mass units in Unitful.jl and UnitfulAstro.jl can be used.

Returns

• A dictionary with two entries.
  • "Z" ⟹ Metallicities of the particles.
  • "unit" ⟹ The unit of mass used, i.e. is a pass-through of mass_unit.
  • "type" ⟹ Particle type, i.e. is a pass-through of type.

get_position(snapshot::String; <keyword arguments>)::Dict{String, Any}

Get the coordinates of all the particles at a specific time step.

Arguments

• snapshot::String: Path to a given snapshot.

• sim_cosmo::Int64 = 0: Value of the GADGET variable ComovingIntegrationOn:

  • 0 ⟶ Newtonian simulation (static universe).
  • 1 ⟶ Cosmological simulation (expanding universe).

• center::Union{String, Nothing} = nothing: How to adjust the center of mass.

  • nothing: No adjustments to the center of mass are made.
  • "local": Each type of particle gets its center of mass to (0, 0, 0) independently.
  • "baryon": Baryons and dark matter get their centers of mass to (0, 0, 0) independently.
  • "global": The center of mass of the whole system gets to (0, 0, 0).

• filter_function::Function = pass_all: A function with the signature:

  foo(snap_file::String, type::String)::Vector{Int64}

  See the function pass_all for an example. By default, no particles are filtered.

• box_size::Unitful.Quantity = 1000.0UnitfulAstro.kpc: Size of the plotting region if vacuum boundary conditions were used. It has to have units but they don't have to be the same as length_unit.

• length_unit::Unitful.FreeUnits = UnitfulAstro.kpc: Unit of length to be used in the output, all available length units in Unitful.jl and UnitfulAstro.jl can be used.

Returns

• A dictionary with six entries.
  • "gas", "dark_matter", "stars" ⟹ 2 dimensional arrays with the positions of the particles of the type given by the key. Each row is a particle and each column correspond to coordinates x, y and z respectively.
  • "box_size" ⟹ The range of values for the plotting of the positions, i.e. a range of ± box_size if vacuum boundary conditions were used, or (0, header.boxsize) if periodic boundary conditions were used. Notice how the side length of the region is 2 * box_size for vacuum boundary conditions and header.boxsize for periodic boundary conditions.
  • "periodic" ⟹ If the boundary condition are periodic.
  • "unit" ⟹ The unit of length used, i.e. is a pass-through of length_unit.

get_sfr_txt(
    source_path::String,
    snapshot::String; 
    <keyword arguments>
)::Dict{Union{Int64, String}, Any}

Get the column data from the sfr.txt file.

Transform from internal units to the ones given by mass_unit, time_unit and sfr_unit.

Warning

This function takes a modified version of sfr.txt generated by a private version of GADGET3. GADGET4 produces a sfr.txt, but it is not compatible with this function.

Arguments

• source_path::String: Path to the directory containing the sfr.txt file.
• snapshot::String: Path to a particular snapshot file, to use its header.
• sim_cosmo::Int64 = 0: Value of the GADGET variable ComovingIntegrationOn:
  • 0 ⟶ Newtonian simulation (static universe).
  • 1 ⟶ Cosmological simulation (expanding universe).
• mass_unit::Unitful.FreeUnits = UnitfulAstro.Msun: Unit of mass to be used in the output, all available mass units in Unitful.jl and UnitfulAstro.jl can be used.
• time_unit::Unitful.FreeUnits = UnitfulAstro.Myr: Unit of time to be used in the output, all available time units in Unitful.jl and UnitfulAstro.jl can be used.
• sfr_unit::Unitful.FreeUnits = UnitfulAstro.Msun / UnitfulAstro.yr: Unit of mass/time to be used in the output, all available time and mass units in Unitful.jl and UnitfulAstro.jl can be used.

Returns

• A dictionary with seven entries.
  • 1 ⟹ The first column (time).
  • 2 ⟹ The second column (total mass - probability).
  • 3 ⟹ The third column (SFR - original GADGET).
  • 4 ⟹ The fourth column (SFR - probability).
  • 5 ⟹ The fifth column (real total mass).
  • 6 ⟹ The sixth column (real SFR).
  • "units" ⟹ Units used, i.e. is a pass-through of mass_unit, time_unit and sfr_unit.

function get_snapshot_path(
    base_name::String,
    source_path::String,
)::Dict{String, Vector{String}}

Find the paths to the GADGET output files, grouping them by snapshot.

Arguments

• base_name::String: Base name of the snapshot files, set in the GADGET variable SnapshotFileBase.
• source_path::String: Path to the directory containing the snapshot files, set in the GADGET variable OutputDir.

Returns

• A dictionary with two entries.
  • "numbers" ⟹ The numbers that characterize each snapshot.
  • "snap_files" ⟹ The paths to the snapshot files.

get_temperature(snapshot::String; <keyword arguments>)::Dict{String,Any}

Get the temperature of the gas particles at a specific time step.

To compute the temperature we use

\[T = (\gamma - 1) \, \frac{e \, m}{k_B} \, ,\]

where $\gamma$ is the adiabatic index, $e$ is the internal energy per unit mass, $m$ the mass per particle (protons and electrons) and $k_B$ is the Boltzmann constant. In particular, we take $\gamma = 5/3$. For how we compute $e$ and $m$ see the comments in the source code of this function.

Arguments

• snapshot::String: Path to a given snapshot.

• sim_cosmo::Int64 = 0: Value of the GADGET variable ComovingIntegrationOn:

  • 0 ⟶ Newtonian simulation (static universe).
  • 1 ⟶ Cosmological simulation (expanding universe).

• filter_function::Function = pass_all: A function with the signature:

  foo(snap_file::String, type::String)::Vector{Int64}

  See the function pass_all for an example. By default, no particles are filtered.

• temp_unit::Unitful.FreeUnits = Unitful.K: Unit of temperature to be used in the output, all available temperature units in Unitful.jl and UnitfulAstro.jl can be used.

Returns

• A dictionary with two entries.
  • "temperature" ⟹ Temperatures of the particles.
  • "unit" ⟹ The unit of temperature used, i.e. is a pass-through of temp_unit.

get_time_evolution(snap_files::Vector{String}; <keyword arguments>)::Dict{String, Any}

Get the time series of several parameters for the whole simulation.

The parameters are:

• "scale_factor"
• "redshift"
• "clock_time" (Physical time)
• "sfr" (SFR)
• "sfr_prob" (SFR probability - Not normalized)
• "gas_number" (Gas particle number)
• "dm_number" (Dark matter particle number)
• "star_number" (Star number)
• "gas_mass" (Total gas mass)
• "dm_mass" (Total dark matter mass)
• "star_mass" (Total star mass)
• "gas_density" (Global gas density)
• "gas_frac" (Gas fraction)
• "dm_frac" (Dark matter fraction)
• "star_frac" (Star fraction)
• "gas_bar_frac" (Baryonic gas fraction)
• "star_bar_frac" (Baryonic star fraction)

Arguments

• snap_files::Vector{String}: Output of the function get_snapshot_path corresponding to the key "snap_files", containing an Array with the paths to the snapshots.

• sim_cosmo::Int64 = 0: Value of the GADGET variable ComovingIntegrationOn:

  • 0 ⟶ Newtonian simulation (static universe).
  • 1 ⟶ Cosmological simulation (expanding universe).

• filter_function::Function = pass_all: A function with the signature:

  foo(snap_file::String, type::String)::Vector{Int64}

  See the function pass_all for an example. By default, no particles are filtered.

• mass_unit::Unitful.FreeUnits = UnitfulAstro.Msun: Unit of mass to be used in the output, all available mass units in Unitful.jl and UnitfulAstro.jl can be used.

• time_unit::Unitful.FreeUnits = UnitfulAstro.Myr: Unit of time to be used in the output, all available time units in Unitful.jl and UnitfulAstro.jl can be used.

• sfr_unit::Unitful.FreeUnits = UnitfulAstro.Msun / UnitfulAstro.yr: Unit of mass/time to be used in the output, all available time and mass units in Unitful.jl and UnitfulAstro.jl can be used.

• length_unit::Unitful.FreeUnits = UnitfulAstro.kpc: Unit of length to be used in the output, all available length units in Unitful.jl and UnitfulAstro.jl can be used.

• density_unit::Unitful.FreeUnits = UnitfulAstro.Msun / UnitfulAstro.kpc^3: Unit of density to be used in the output, all available density units in Unitful.jl and UnitfulAstro.jl can be used.

Returns

• A dictionary.
  • "{property}" ⟹ Numeric values of the property in the key (one value per snapshot) for the whole simulation.
  • "units" ⟹ Units used, for easy piping with other functions.
  • "labels" ⟹ Labels to be used when plotting the quantities.