Shape Profiling

Classes for Shape Profiling

The shape_profs_classes module defines the DensShapeProfs and DensShapeProfsGadget classes that provide shape profiling capabilities. They inherit from the DensShapeProfsBase class (not relevant for the user). In addition to shape profiling, they also provide an interface to density profiling, including ellipsoidal shell-based density profiling.

class shape_profs.shape_profs_classes.DensShapeProfs

Bases: DensShapeProfsBase

Class for density profile calculations

Its public methods are the same as those of DensShapeProfsBase: getShapeCatLocal(), getShapeCatGlobal(), vizLocalShapes(), vizGlobalShapes(), plotGlobalEpsHist(), plotLocalEpsHist(), plotGlobalTHist(), plotLocalTHist(), dumpShapeCatLocal(), dumpShapeCatGlobal(), getR200(), getIdxCat(), getXYZMasses(), getMassesCenters(), _getMassesCenters(), estDensProfs(), fitDensProfs(), estConcentrations(), plotDensProfs(), getObjInfo()

Parameters

• xyz ((N2,3) floats, N2 >> N1) – positions of all simulation particles in config.InUnitLength_in_cm

• masses ((N2,) floats) – masses of all simulation particles in config.InUnitMass_in_g

• idx_cat (list of length N1) – each entry of the list is a list containing indices of particles belonging to an object

• r200 ((N1,) floats) – R_200 radii of the parent halos in config.InUnitLength_in_cm

• L_BOX (float) – simulation box side length in config.InUnitLength_in_cm

• SNAP (string) – snapshot identifier, e.g. ‘024’

• VIZ_DEST (string) – visualization folder

• CAT_DEST (string) – catalogue destination

• MIN_NUMBER_PTCS (int) – minimum number of particles for object to qualify for morphology calculation

• CENTER (str) – shape quantities will be calculated with respect to CENTER = ‘mode’ (point of highest density) or ‘com’ (center of mass) of each halo

__init__()

Parameters

• xyz ((N2,3) floats, N2 >> N1) – positions of all simulation particles in config.InUnitLength_in_cm

• masses ((N2,) floats) – masses of all simulation particles in config.InUnitMass_in_g

• idx_cat (list of length N1) – each entry of the list is a list containing indices of particles belonging to an object

• r200 ((N1,) floats) – R_200 radii of the parent halos in config.InUnitLength_in_cm

• L_BOX (float) – simulation box side length in config.InUnitLength_in_cm

• SNAP (string) – snapshot identifier, e.g. ‘024’

• VIZ_DEST (string) – visualization folder

• CAT_DEST (string) – catalogue destination

• MIN_NUMBER_PTCS (int) – minimum number of particles for object to qualify for morphology calculation

• CENTER (str) – shape quantities will be calculated with respect to CENTER = ‘mode’ (point of highest density) or ‘com’ (center of mass) of each halo

class shape_profs.shape_profs_classes.DensShapeProfsBase

Bases: DensProfsBase

Class for density profile and shape profile calculations

Its public methods are getShapeCatLocal(), getShapeCatGlobal(), vizLocalShapes(), vizGlobalShapes(), plotGlobalEpsHist(), plotLocalEpsHist(), plotGlobalTHist(), plotLocalTHist(), dumpShapeCatLocal(), dumpShapeCatGlobal() and those of DensProfsBase: getR200()`, getIdxCat(), getXYZMasses(), getMassesCenters(), _getMassesCenters(), estDensProfs(), fitDensProfs(), estConcentrations(), plotDensProfs(), getObjInfo().

Parameters

• xyz ((N2,3) floats, N2 >> N1) – positions of all simulation particles in Mpc/h (internal length units)

• masses ((N2,) floats) – masses of all simulation particles in 10^10*M_sun/h (internal mass units)

• idx_cat ((N3,) integers) – contains indices of particles belonging to an object

• r200 ((N1,) floats) – R_200 radii of the parent halos in Mpc/h (internal length units)

• obj_size ((N1,) integers) – indicates how many particles are in each object

• SNAP (string) – snapshot identifier, e.g. ‘024’

• L_BOX (float) – simulation box side length in Mpc/h (internal length units)

• MIN_NUMBER_PTCS (int) – minimum number of particles for object to qualify for morphology calculation

• CENTER (str) – shape quantities will be calculated with respect to CENTER = ‘mode’ (point of highest density) or ‘com’ (center of mass) of each halo

• VIZ_DEST (string) – visualization folder

• CAT_DEST (string) – catalogue destination

• SUFFIX (string) – either ‘_dm_’ or ‘_gx_’ or ‘_’ (latter for CosmicProfsDirect)

__init__()

Parameters

• xyz ((N2,3) floats, N2 >> N1) – positions of all simulation particles in Mpc/h (internal length units)

• masses ((N2,) floats) – masses of all simulation particles in 10^10*M_sun/h (internal mass units)

• idx_cat ((N3,) integers) – contains indices of particles belonging to an object

• r200 ((N1,) floats) – R_200 radii of the parent halos in Mpc/h (internal length units)

• obj_size ((N1,) integers) – indicates how many particles are in each object

• SNAP (string) – snapshot identifier, e.g. ‘024’

• L_BOX (float) – simulation box side length in Mpc/h (internal length units)

• MIN_NUMBER_PTCS (int) – minimum number of particles for object to qualify for morphology calculation

• CENTER (str) – shape quantities will be calculated with respect to CENTER = ‘mode’ (point of highest density) or ‘com’ (center of mass) of each halo

• VIZ_DEST (string) – visualization folder

• CAT_DEST (string) – catalogue destination

• SUFFIX (string) – either ‘_dm_’ or ‘_gx_’ or ‘_’ (latter for CosmicProfsDirect)

dumpShapeCatGlobal()

Dumps all relevant global shape data into CAT_DEST

Parameters

• obj_numbers (list of int) – list of object indices of interest

• katz_config (dictionary) – dictionary with parameters to the Katz algorithm, with fields ‘ROverR200’, ‘IT_TOL’, ‘IT_WALL’, ‘IT_MIN’, ‘REDUCED’, ‘SHELL_BASED’

dumpShapeCatLocal()

Dumps all relevant local shape data into CAT_DEST

Parameters

• obj_numbers (list of int) – list of object indices of interest

• katz_config (dictionary) – dictionary with parameters to the Katz algorithm, with fields ‘ROverR200’, ‘IT_TOL’, ‘IT_WALL’, ‘IT_MIN’, ‘REDUCED’, ‘SHELL_BASED’

getShapeCatGlobal()

Get all relevant global shape data

Parameters

• obj_numbers (list of int) – list of object indices of interest

• katz_config (dictionary) – dictionary with parameters to the Katz algorithm, with fields ‘ROverR200’, ‘IT_TOL’, ‘IT_WALL’, ‘IT_MIN’, ‘REDUCED’, ‘SHELL_BASED’

Returns

d in units of config.OutUnitLength_in_cm, q, s, minor, inter, major, obj_centers in units of config.OutUnitLength_in_cm, obj_masses in units of config.OutUnitMass_in_g

Return type

structured array, containing 3 x (number_of_objs,) double arrays, 3 x (number_of_objs, 3) double arrays

getShapeCatLocal()

Get all relevant local shape data

Parameters

• obj_numbers (list of int) – list of object indices of interest

• katz_config (dictionary) – dictionary with parameters to the Katz algorithm, with fields ‘ROverR200’, ‘IT_TOL’, ‘IT_WALL’, ‘IT_MIN’, ‘REDUCED’, ‘SHELL_BASED’

Returns

d in units of config.OutUnitLength_in_cm, q, s, minor, inter, major, obj_centers in units of config.OutUnitLength_in_cm, obj_masses in units of config.OutUnitMass_in_g

Return type

structured array, containing 3 x (number_of_objs, r_res) double arrays, 3 x (number_of_objs, r_res, 3) double arrays

plotGlobalEpsHist()

Plot global ellipticity histogram

Parameters

• HIST_NB_BINS (int) – number of histogram bins

• obj_numbers (list of int) – list of object indices of interest

plotGlobalTHist()

Plot global triaxiality histogram

Parameters

• katz_dubinski_config (dictionary) – dictionary with parameters to the Katz-Dubinski algorithm, with fields ‘ROverR200’, ‘IT_TOL’, ‘IT_WALL’, ‘IT_MIN’, ‘REDUCED’, ‘SHELL_BASED’

• HIST_NB_BINS (int) – number of histogram bins

• obj_numbers (list of int) – list of object indices of interest

• katz_config (dictionary) – dictionary with parameters to the Katz algorithm, with fields ‘ROverR200’, ‘IT_TOL’, ‘IT_WALL’, ‘IT_MIN’, ‘REDUCED’, ‘SHELL_BASED’

plotLocalEpsHist()

Plot local ellipticity histogram at depth frac_r200

Parameters

• frac_r200 (float) – depth of objects to plot ellipticity, in units of R200

• HIST_NB_BINS (int) – number of histogram bins

• obj_numbers (list of int) – list of object indices of interest

plotLocalTHist()

Plot local triaxiality histogram at depth frac_r200

Parameters

• HIST_NB_BINS (int) – number of histogram bins

• frac_r200 (float) – depth of objects to plot triaxiality, in units of R200

• obj_numbers (list of int) – list of object indices of interest

• katz_config (dictionary) – dictionary with parameters to the Katz algorithm, with fields ‘ROverR200’, ‘IT_TOL’, ‘IT_WALL’, ‘IT_MIN’, ‘REDUCED’, ‘SHELL_BASED’

plotShapeProfs()

Draws shape profiles, also mass bin-decomposed ones

Parameters

• nb_bins (int) – Number of mass bins to plot density profiles for

• obj_numbers (list of int) – list of object indices of interest

• katz_config (dictionary) – dictionary with parameters to the Katz algorithm, with fields ‘ROverR200’, ‘IT_TOL’, ‘IT_WALL’, ‘IT_MIN’, ‘REDUCED’, ‘SHELL_BASED’

vizGlobalShapes()

Visualize global shape of objects with numbers obj_numbers

Parameters

• obj_numbers (list of int) – list of object indices of interest

• katz_config (dictionary) – dictionary with parameters to the Katz algorithm, with fields ‘ROverR200’, ‘IT_TOL’, ‘IT_WALL’, ‘IT_MIN’, ‘REDUCED’, ‘SHELL_BASED’

vizLocalShapes()

Visualize local shape of objects with numbers obj_numbers

Parameters

• obj_numbers (list of int) – list of object indices of interest

• katz_config (dictionary) – dictionary with parameters to the Katz algorithm, with fields ‘ROverR200’, ‘IT_TOL’, ‘IT_WALL’, ‘IT_MIN’, ‘REDUCED’, ‘SHELL_BASED’

class shape_profs.shape_profs_classes.DensShapeProfsGadget

Bases: DensShapeProfsBase

Class for density profile and shape profile calculations for Gadget-style HDF5 data

Its public methods are getShapeCatVelLocal(), getShapeCatVelGlobal(), dumpShapeVelCatLocal(), dumpShapeVelCatGlobal(), getXYZMasses(), _getXYZMasses(), getVelXYZ(), _getVelXYZ(), getObjInfoGadget(), getHeader()``and those of ``DensShapeProfsBase: getShapeCatLocal(), getShapeCatGlobal(), vizLocalShapes(), vizGlobalShapes(), plotGlobalEpsHist(), plotLocalEpsHist(), plotGlobalTHist(), plotLocalTHist(), dumpShapeCatLocal(), dumpShapeCatGlobal(), getR200(), getIdxCat(), getXYZMasses(), getMassesCenters(), _getMassesCenters(), estDensProfs(), fitDensProfs(), estConcentrations(), plotDensProfs(), getObjInfo().

Parameters

• SNAP_DEST (string) – where we can find the snapshot

• GROUP_DEST (string) – where we can find the group files

• OBJ_TYPE (str) – which simulation particles to consider, ‘dm’, ‘gas’ or ‘stars’

• SNAP (string) – snapshot identifier, e.g. ‘024’

• VIZ_DEST (string) – visualization folder

• CAT_DEST (string) – catalogue destination

• RVIR_OR_R200 (str) – ‘Rvir’ if we want quantities (e.g. r_over_r200) to be expressed with respect to the virial radius R_vir, ‘R200’ for the overdensity radius R_200

• MIN_NUMBER_PTCS (int) – minimum number of particles for object to qualify for morphology calculation

• CENTER (str) – shape quantities will be calculated with respect to CENTER = ‘mode’ (point of highest density) or ‘com’ (center of mass) of each halo

__init__()

Parameters

• SNAP_DEST (string) – where we can find the snapshot

• GROUP_DEST (string) – where we can find the group files

• OBJ_TYPE (str) – which simulation particles to consider, ‘dm’, ‘gas’ or ‘stars’

• SNAP (string) – snapshot identifier, e.g. ‘024’

• VIZ_DEST (string) – visualization folder

• CAT_DEST (string) – catalogue destination

• RVIR_OR_R200 (str) – ‘Rvir’ if we want quantities (e.g. r_over_r200) to be expressed with respect to the virial radius R_vir, ‘R200’ for the overdensity radius R_200

• MIN_NUMBER_PTCS (int) – minimum number of particles for object to qualify for morphology calculation

• CENTER (str) – shape quantities will be calculated with respect to CENTER = ‘mode’ (point of highest density) or ‘com’ (center of mass) of each halo

dumpShapeVelCatGlobal()

Dumps all relevant global velocity shape data into CAT_DEST

Parameters

• obj_numbers (list of int) – list of object indices of interest

• katz_config (dictionary) – dictionary with parameters to the Katz algorithm, with fields ‘ROverR200’, ‘IT_TOL’, ‘IT_WALL’, ‘IT_MIN’, ‘REDUCED’, ‘SHELL_BASED’

dumpShapeVelCatLocal()

Dumps all relevant local velocity shape data into CAT_DEST

Parameters

• obj_numbers (list of int) – list of object indices of interest

• katz_config (dictionary) – dictionary with parameters to the Katz algorithm, with fields ‘ROverR200’, ‘IT_TOL’, ‘IT_WALL’, ‘IT_MIN’, ‘REDUCED’, ‘SHELL_BASED’

getHeader()

Get header of first file in snapshot

getIdxCat()

Fetch catalogue

Return idx_cat

contains indices of particles belonging to an object, obj_size: number of particles in each object

Return type

(N3) integers and (N1,) integers

getObjInfoGadget()

Print basic info about the objects

getR200()

Fetch R200 values

Return obj_r200

R200 value of parent halos in config.OutUnitLength_in_cm

Return type

(N1,) floats

getShapeCatVelGlobal()

Get all relevant global velocity shape data

Parameters

• obj_numbers (list of int) – list of object indices of interest

• katz_config (dictionary) – dictionary with parameters to the Katz algorithm, with fields ‘ROverR200’, ‘IT_TOL’, ‘IT_WALL’, ‘IT_MIN’, ‘REDUCED’, ‘SHELL_BASED’

Returns

d in units of config.OutUnitLength_in_cm, q, s, minor, inter, major, obj_centers in units of config.OutUnitLength_in_cm, obj_masses in units of config.OutUnitMass_in_g

Return type

structured array, containing 3 x (number_of_objs,) double arrays, 3 x (number_of_objs, 3) double arrays

getShapeCatVelLocal()

Get all relevant local velocity shape data

Parameters

• obj_numbers (list of int) – list of object indices of interest

• katz_config (dictionary) – dictionary with parameters to the Katz algorithm, with fields ‘ROverR200’, ‘IT_TOL’, ‘IT_WALL’, ‘IT_MIN’, ‘REDUCED’, ‘SHELL_BASED’

Returns

d in units of config.OutUnitLength_in_cm, q, s, minor, inter, major, obj_centers in units of config.OutUnitLength_in_cm, obj_masses in units of config.OutUnitMass_in_g

Return type

structured array, containing 3 x (number_of_objs, r_res) double arrays, 3 x (number_of_objs, r_res, 3) double arrays

getVelXYZ()

Retrieve velocities of particles

Return velxyz

velocity array in config.OutUnitVelocity_in_cm_per_s

Return type

(N2,3) floats

getXYZMasses()

Retrieve positions and masses of particles

Return xyz, masses

positions in config.OutUnitLength_in_cm and masses in config.OutUnitMass_in_g

Return type

(N2,3) floats, (N2,) floats

Shape profile estimation algorithms

The shape_profs_algos module contains the enclosed ellipsoid-based and the ellipsoidal shell-based shape estimation iteration algorithms.

shape_profs.shape_profs_algos.calcMorphGlobal(double[:, :] xyz, double[:] masses, double[:] r200, int[:] idx_cat, int[:] obj_size, double L_BOX, double IT_TOL, int IT_WALL, int IT_MIN, unicode CENTER, double SAFE, bool reduced)

Calculates the overall shape catalogue

Calls calcObjMorphGlobal() in a parallelized manner.

Calculates the overall axis ratios and eigenframe for each object.

Parameters

• xyz ((N2 x 3) floats) – positions of all (DM or star) particles in simulation box

• masses ((N2 x 1) floats) – masses of the particles expressed in unit mass

• r200 ((N1,) floats) – R_200 radii of the parent halos

• idx_cat ((N3,) integers) – contains indices of particles belonging to an object

• obj_size ((N1,) integers) – indicates how many particles are in each object

• L_BOX (float, units: Mpc/h) – simulation box side length

• IT_TOL (float) – convergence tolerance, eigenvalue fractions must differ by less than IT_TOL for iteration to stop

• IT_WALL (float) – maximum permissible number of iterations

• IT_MIN (int) – minimum number of particles (DM or star particle) in any iteration; if undercut, shape is unclassified

• CENTER (str) – shape quantities will be calculated with respect to CENTER = ‘mode’ (point of highest density) or ‘com’ (center of mass) of each halo

• SAFE (float) – ellipsoidal radius will be maxdist(COM,point)+SAFE where point is any point in the point cloud. The larger the better.

• reduced (boolean) – whether or not reduced shape tensor (1/r^2 factor)

Returns

d, q, s, eigframe, centers, masses

Return type

(N3,) floats (for d, q, s, eigframe (x3)), (N3, 3) floats (for centers), (N3,) floats (for masses)

shape_profs.shape_profs_algos.calcMorphGlobalVelDisp(double[:, :] xyz, double[:, :] vxyz, double[:] masses, double[:] r200, int[:] idx_cat, int[:] obj_size, double L_BOX, double IT_TOL, int IT_WALL, int IT_MIN, unicode CENTER, double SAFE, bool reduced)

Calculates the global velocity dipsersion shape catalogue

Calls calcObjMorphGlobalVelDisp() in a parallelized manner.

Calculates the overall axis ratios and eigenframe for each object.

Parameters

• xyz ((N2 x 3) floats) – positions of all (DM or star) particles in simulation box

• vxyz ((N2 x 3) floats) – velocities of all (DM or star) particles in simulation box

• masses ((N2 x 1) floats) – masses of the particles expressed in unit mass

• r200 ((N1,) floats) – R_200 radii of the parent halos

• idx_cat ((N3,) integers) – contains indices of particles belonging to an object

• obj_size ((N1,) integers) – indicates how many particles are in each object

• L_BOX (float, units: Mpc/h) – simulation box side length

• MIN_NUMBER_PTCS (int) – minimum number of particles for object to qualify for morphology calculation

• IT_TOL (float) – convergence tolerance, eigenvalue fractions must differ by less than IT_TOL for iteration to stop

• IT_WALL (float) – maximum permissible number of iterations

• IT_MIN (int) – minimum number of particles (DM or star particle) in any iteration; if undercut, shape is unclassified

• CENTER (str) – shape quantities will be calculated with respect to CENTER = ‘mode’ (point of highest density) or ‘com’ (center of mass) of each halo

• SAFE (float) – ellipsoidal radius will be maxdist(COM,point)+SAFE where point is any point in the point cloud. The larger the better.

• reduced (boolean) – whether or not reduced shape tensor (1/r^2 factor)

Returns

d, q, s, eigframe, centers, masses

Return type

(N3, D_BINS + 1) floats (for d, q, s, eigframe (x3)), (N3, 3) floats (for centers), (N3,) floats (for masses)

shape_profs.shape_profs_algos.calcMorphLocal(double[:, :] xyz, double[:] masses, double[:] r200, int[:] idx_cat, int[:] obj_size, double L_BOX, double[:] r_over_r200, double IT_TOL, int IT_WALL, int IT_MIN, unicode CENTER, bool reduced, bool shell_based)

Calculates the local shape catalogue

Calls calcObjMorphLocal() in a parallelized manner.

Calculates the axis ratios for the range [ r200 x r_over_r200[0], r200 x r_over_r200[-1]] from the centers, for each object.

Parameters

• xyz ((N2 x 3) floats) – positions of all (DM or star) particles in simulation box

• masses ((N2 x 1) floats) – masses of the particles expressed in unit mass

• r200 ((N1,) floats) – R_200 radii of the parent halos

• idx_cat ((N3,) integers) – contains indices of particles belonging to an object

• obj_size ((N1,) integers) – indicates how many particles are in each object

• L_BOX (float, units: Mpc/h) – simulation box side length

• r_over_r200 ((r_res,) floats) – normalized radii at which shape profiles should be estimated

• IT_TOL (float) – convergence tolerance, eigenvalue fractions must differ by less than IT_TOL for iteration to stop

• IT_WALL (float) – maximum permissible number of iterations

• IT_MIN (int) – minimum number of particles (DM or star particle) in any iteration; if undercut, shape is unclassified

• CENTER (str) – shape quantities will be calculated with respect to CENTER = ‘mode’ (point of highest density) or ‘com’ (center of mass) of each halo

• reduced (boolean) – whether or not reduced shape tensor (1/r^2 factor)

• shell_based (boolean) – whether shell-based or ellipsoid-based algorithm should be run

Returns

d, q, s, eigframe, centers, masses, l_succeed: list of object indices for which morphology could be determined at R200 (length: N3)

Return type

(N3, D_BINS + 1) floats (for d, q, s, eigframe (x3)), (N3, 3) floats (for centers), (N3,) floats (for masses), N3-list of ints for l_succeed

shape_profs.shape_profs_algos.calcMorphLocalVelDisp(double[:, :] xyz, double[:, :] vxyz, double[:] masses, double[:] r200, int[:] idx_cat, int[:] obj_size, double L_BOX, double[:] r_over_r200, double IT_TOL, int IT_WALL, int IT_MIN, unicode CENTER, bool reduced, bool shell_based)

Calculates the local velocity dispersion shape catalogue

Calls calcObjMorphLocalVelDisp() in a parallelized manner.

Calculates the overall axis ratios and eigenframe for each object.

Parameters

• xyz ((N2 x 3) floats) – positions of all (DM or star) particles in simulation box

• vxyz ((N2 x 3) floats) – velocities of all (DM or star) particles in simulation box

• masses ((N2 x 1) floats) – masses of the particles expressed in unit mass

• r200 ((N1,) floats) – R_200 radii of the parent halos

• idx_cat ((N3,) integers) – contains indices of particles belonging to an object

• obj_size ((N1,) integers) – indicates how many particles are in each object

• L_BOX (float, units: Mpc/h) – simulation box side length

• MIN_NUMBER_PTCS (int) – minimum number of particles for object to qualify for morphology calculation

• r_over_r200 ((r_res,) floats) – normalized radii at which shape profiles should be estimated

• IT_TOL (float) – convergence tolerance, eigenvalue fractions must differ by less than IT_TOL for iteration to stop

• IT_WALL (float) – maximum permissible number of iterations

• IT_MIN (int) – minimum number of particles (DM or star particle) in any iteration; if undercut, shape is unclassified

• CENTER (str) – shape quantities will be calculated with respect to CENTER = ‘mode’ (point of highest density) or ‘com’ (center of mass) of each halo

• reduced (boolean) – whether or not reduced shape tensor (1/r^2 factor)

• shell_based (boolean) – whether shell-based or ellipsoid-based algorithm should be run

Returns

d, q, s, eigframe, centers, masses, l_succeed: list of object indices for which morphology could be determined at R200 (length: N3)

Return type

(N3, D_BINS + 1) floats (for d, q, s, eigframe (x3)), (N3, 3) floats (for centers), (N3,) floats (for masses), N3-list of ints for l_succeed

Shape profiling tools

The shape_profs_tools module provides shape-related tools e.g. how to calculate the complex ellipticity for a particle cloud given a line-of-sight.

shape_profs.shape_profs_tools.getEpsilon(idx_cat, obj_size, xyz, masses, L_BOX, CENTER, angle=0.0)

Calculate the complex ellipticity (z-projected)

It is obtained from the shape tensor = centred (wrt mode) second mass moment tensor

Parameters

• idx_cat ((N3) integers) – contains indices of particles belonging to an object

• obj_size ((N1,) integers) – indicates how many particles are in each object

• xyz ((N^3x3) floats) – coordinates of particles of type 1 or type 4

• masses ((N^3x1) floats) – masses of particles of type 1 or type 4

• L_BOX (float, units: Mpc/h) – simulation box side length

• CENTER (str) – shape quantities will be calculated with respect to CENTER = ‘mode’ (point of highest density) or ‘com’ (center of mass) of each halo

• angle (float) – rotation of objects around z-axis before ellipticity is calculated (z-projected)

Returns

complex ellipticity

Return type

complex scalar

shape_profs.shape_profs_tools.getGlobalEpsHist(xyz, masses, idx_cat, obj_size, L_BOX, CENTER, VIZ_DEST, SNAP, suffix='_', HIST_NB_BINS=11)

Plot ellipticity histogram

Parameters

• xyz ((N^3x3) floats) – coordinates of particles of type 1 or type 4, in Mpc/h

• masses ((N^3x1) floats) – masses of particles of type 1 or type 4, in 10^10*M_sun/h

• idx_cat ((N3) integers) – contains indices of particles belonging to an object

• obj_size ((N1,) integers) – indicates how many particles are in each object

• L_BOX (float, units: Mpc/h) – simulation box side length

• CENTER (str) – shape quantities will be calculated with respect to CENTER = ‘mode’ (point of highest density) or ‘com’ (center of mass) of each halo

• VIZ_DEST (string) – visualisation folder destination

• SNAP (string) – e.g. ‘024’

• suffix (string) – either ‘_dm_’ or ‘_gx_’ or ‘’ (latter for DensShapeProfs)

• HIST_NB_BINS (int) – Number of histogram bins

shape_profs.shape_profs_tools.getGlobalTHist(VIZ_DEST, SNAP, start_time, obj_masses, obj_centers, d, q, s, major_full, HIST_NB_BINS, MASS_UNIT, suffix='_')

Plot triaxiality T histogram

Parameters

• VIZ_DEST (string) – visualisation folder destination

• SNAP (string) – e.g. ‘024’

• start_time (float) – time of start of shape analysis

• obj_masses ((N,) floats) – masses of objects in 10^10*M_sun/h

• obj_centers ((N,3) floats) – centers of objects, each coordinate in Mpc/h

• d ((N, D_BINS+1) floats) – ellipsoidal radii at which shape profiles have been calculated

• q ((N, D_BINS+1) floats) – q-values

• s ((N, D_BINS+1) floats) – s-values

• major_full ((N, D_BINS+1, 3) floats) – major axes at each radii

• HIST_NB_BINS (int) – Number of histogram bins

• MASS_UNIT (float) – conversion factor from previous mass unit to M_sun/h

• suffix (string) – either ‘_dm_’ or ‘_gx_’ or ‘’ (latter for DensShapeProfs)

shape_profs.shape_profs_tools.getLocalEpsHist(xyz, masses, r200, idx_cat, obj_size, L_BOX, CENTER, VIZ_DEST, SNAP, frac_r200, suffix='_', HIST_NB_BINS=11)

Plot ellipticity histogram

Parameters

• xyz ((N^3x3) floats) – coordinates of particles of type 1 or type 4, in Mpc/h

• masses ((N^3x1) floats) – masses of particles of type 1 or type 4, in 10^10*M_sun/h

• r200 ((N1,) floats) – R_200 radii of the parent halos

• idx_cat ((N3) integers) – contains indices of particles belonging to an object

• obj_size ((N1,) integers) – indicates how many particles are in each object

• L_BOX (float, units: Mpc/h) – simulation box side length

• CENTER (str) – shape quantities will be calculated with respect to CENTER = ‘mode’ (point of highest density) or ‘com’ (center of mass) of each halo

• VIZ_DEST (string) – visualisation folder destination

• SNAP (string) – e.g. ‘024’

• frac_r200 (float) – depth of objects to plot triaxiality, in units of R200

• suffix (string) – either ‘_dm_’ or ‘_gx_’ or ‘’ (latter for DensShapeProfs)

• HIST_NB_BINS (int) – Number of histogram bins

shape_profs.shape_profs_tools.getLocalTHist(VIZ_DEST, SNAP, r_over_r200, r200, start_time, obj_masses, obj_centers, d, q, s, major_full, HIST_NB_BINS, frac_r200, MASS_UNIT, suffix='_')

Plot triaxiality T histogram

Parameters

• VIZ_DEST (string) – visualisation folder destination

• SNAP (string) – e.g. ‘024’

• r_over_r200 ((D_BINS+1,) floats) – normalized radii at which shape profiles are estimated

• r200 ((N,) floats) – each entry gives the R_200 radius of the parent halo in Mpc/h (internal length units)

• start_time (float) – time of start of shape analysis

• obj_masses ((N,) floats) – masses of objects, in 10^10*M_sun/h

• obj_centers ((N,3) floats) – centers of objects, each coordinate in Mpc/h

• d ((N, D_BINS+1) floats) – ellipsoidal radii at which shape profiles have been calculated

• q ((N, D_BINS+1) floats) – q-values

• s ((N, D_BINS+1) floats) – s-values

• major_full ((N, D_BINS+1, 3) floats) – major axes at each radii

• HIST_NB_BINS (int) – Number of histogram bins

• frac_r200 (float) – depth of objects to plot triaxiality, in units of R200

• MASS_UNIT (float) – conversion factor from previous mass unit to M_sun/h

• suffix (string) – either ‘_dm_’ or ‘_gx_’ or ‘’ (latter for DensShapeProfs)

shape_profs.shape_profs_tools.getShape(d, param_interest, ERROR_METHOD, r_over_r200, r200)

Get average profile for param_interest (which is defined at all values of d) at all ellipsoidal radii Rs

Parameters

• d ((N1,N2) floats) – param_interest is defined at all ellipsoidal radii d

• param_interest ((N1,N2) floats) – the quantity of interest defined at all ellipsoidal radii d

• ERROR_METHOD (string) – mean (if ERROR_METHOD == “bootstrap” or “SEM”) or median (if ERROR_METHOD == “median_quantile”) and the +- 1 sigma error attached

• r_over_r200 ((N2,) floats) – normalized radii at which shape profiles are estimated

• r200 ((N1,) floats) – each entry gives the R_200 radius of the parent halo in Mpc/h (internal length units)

Returns

mean/median, err_low, err_high

Return type

float, float, float

shape_profs.shape_profs_tools.getShapeMs(d, idx_groups, group, param_interest, ERROR_METHOD, r_over_r200, r200)

Similar to getShape, but with mass-splitting

shape_profs.shape_profs_tools.getShapeProfs(VIZ_DEST, SNAP, r_over_r200, r200, start_time, obj_masses, obj_centers, d, q, s, major_full, nb_bins, MASS_UNIT=10000000000.0, suffix='_')

Create a series of plots to analyze object shapes

Plot intertial tensor axis ratios, triaxialities and ellipticity histograms.

Parameters

• VIZ_DEST (string) – visualisation folder destination

• SNAP (string) – e.g. ‘024’

• r_over_r200 ((D_BINS+1,) floats) – normalized radii at which shape profiles are estimated

• r200 ((N,) floats) – each entry gives the R_200 radius of the parent halo in Mpc/h (internal length units)

• start_time (float) – time of start of shape analysis

• obj_masses ((N,) floats) – total mass of objects, in 10^10*M_sun/h

• obj_centers ((N,3) floats) – positions of centers of objects, in Mpc/h

• d ((N, D_BINS+1) floats) – param_interest is defined at all ellipsoidal radii d

• q ((N, D_BINS+1) floats) – intermediate-to-major axis ratios

• s ((N, D_BINS+1) floats) – minor-to-major axis ratios

• major_full ((N,D_BINS+1,3) floats) – major axis vectors

• nb_bins (int) – Number of mass bins to plot density profiles for

• MASS_UNIT (float) – conversion factor from previous mass unit to M_sun/h

• suffix (string) – either ‘_dm_’ or ‘_gx_’ or ‘’ (latter for DensShapeProfs)