2. Clumps: Load Selected Variables and Data Ranges
Simulation Overview
using Mera
info = getinfo(400, "/Volumes/FASTStorage/Simulations/Mera-Tests/manu_sim_sf_L14");[Mera]: 2025-06-30T00:02:26.184
Code: RAMSES
output [400] summary:
mtime: 2018-09-05T09:51:55
ctime: 2025-06-29T20:06:45.267
=======================================================
simulation time: 594.98 [Myr]
boxlen: 48.0 [kpc]
ncpu: 2048
ndim: 3
-------------------------------------------------------
amr: true
level(s): 6 - 14 --> cellsize(s): 750.0 [pc] - 2.93 [pc]
-------------------------------------------------------
hydro: true
hydro-variables: 7 --> (:rho, :vx, :vy, :vz, :p, :var6, :var7)
hydro-descriptor: (:density, :velocity_x, :velocity_y, :velocity_z, :thermal_pressure, :passive_scalar_1, :passive_scalar_2)
γ: 1.6667
-------------------------------------------------------
gravity: true
gravity-variables: (:epot, :ax, :ay, :az)
-------------------------------------------------------
particles: true
- Npart: 5.091500e+05
- Nstars: 5.066030e+05
- Ndm: 2.547000e+03
particle-variables: 5 --> (:vx, :vy, :vz, :mass, :birth)
-------------------------------------------------------
rt: false
-------------------------------------------------------
clumps: true
clump-variables: (:index, :lev, :parent, :ncell, :peak_x, :peak_y, :peak_z, Symbol("rho-"), Symbol("rho+"), :rho_av, :mass_cl, :relevance)
-------------------------------------------------------
namelist-file: false
timer-file: false
compilation-file: true
makefile: true
patchfile: true
=======================================================Select Variables
MERA reads the first line of a clump file to identify the number of columns and their names.
Read all variables (default)
clumps = getclumps(info);[Mera]: Get clump data: 2025-06-30T00:02:29.060
domain:
xmin::xmax: 0.0 :: 1.0 ==> 0.0 [kpc] :: 48.0 [kpc]
ymin::ymax: 0.0 :: 1.0 ==> 0.0 [kpc] :: 48.0 [kpc]
zmin::zmax: 0.0 :: 1.0 ==> 0.0 [kpc] :: 48.0 [kpc]
Read 12 colums:
[:index, :lev, :parent, :ncell, :peak_x, :peak_y, :peak_z, Symbol("rho-"), Symbol("rho+"), :rho_av, :mass_cl, :relevance]
Memory used for data table :61.58203125 KB
-------------------------------------------------------clumps.dataTable with 644 rows, 12 columns:
Columns:
# colname type
──────────────────────
1 index Float64
2 lev Float64
3 parent Float64
4 ncell Float64
5 peak_x Float64
6 peak_y Float64
7 peak_z Float64
8 rho- Float64
9 rho+ Float64
10 rho_av Float64
11 mass_cl Float64
12 relevance Float64The colum names should not be changed, since they are assumed in some functions. The usage of individual descriptor variables will be implemented in the future.
Select several variables w/o a keyword
Currently, the length of the loaded variable list can be modified. E.g. the list can be extended with more names if there are more columns in the data than given by the header in the files.
Load less than the found 12 columns from the header of the clump files; Pass an array with the variables to the keyword argument vars. The order of the variables has to be consistent with the header in the clump files:}
clumps = getclumps(info, vars=[ :index, :lev, :parent, :ncell, :peak_x, :peak_y, :peak_z]);[Mera]: Get clump data: 2025-06-30T00:02:31.597
domain:
xmin::xmax: 0.0 :: 1.0 ==> 0.0 [kpc] :: 48.0 [kpc]
ymin::ymax: 0.0 :: 1.0 ==> 0.0 [kpc] :: 48.0 [kpc]
zmin::zmax: 0.0 :: 1.0 ==> 0.0 [kpc] :: 48.0 [kpc]
Read 7 colums:
[:index, :lev, :parent, :ncell, :peak_x, :peak_y, :peak_z]
Memory used for data table :35.9912109375 KB
-------------------------------------------------------Pass an array that contains the variables without the keyword argument vars. The following order has to be preserved: InfoType-object, variables
clumps = getclumps(info, [ :index, :lev, :parent, :ncell, :peak_x, :peak_y, :peak_z]);[Mera]: Get clump data: 2025-06-30T00:02:32.218
domain:
xmin::xmax: 0.0 :: 1.0 ==> 0.0 [kpc] :: 48.0 [kpc]
ymin::ymax: 0.0 :: 1.0 ==> 0.0 [kpc] :: 48.0 [kpc]
zmin::zmax: 0.0 :: 1.0 ==> 0.0 [kpc] :: 48.0 [kpc]
Read 7 colums:
[:index, :lev, :parent, :ncell, :peak_x, :peak_y, :peak_z]
Memory used for data table :35.9912109375 KB
-------------------------------------------------------clumps.dataTable with 644 rows, 7 columns:
index lev parent ncell peak_x peak_y peak_z
──────────────────────────────────────────────────────
4.0 0.0 4.0 740.0 20.1094 11.5005 23.9604
5.0 0.0 5.0 1073.0 20.1592 11.5122 23.9253
9.0 0.0 9.0 551.0 21.7852 17.855 23.814
12.0 0.0 12.0 463.0 21.8232 17.8608 23.855
13.0 0.0 13.0 2141.0 21.8906 17.2837 23.5415
18.0 0.0 18.0 691.0 21.7822 16.8823 23.7817
19.0 0.0 19.0 608.0 21.75 16.8589 23.7993
20.0 0.0 20.0 1253.0 21.6006 17.5679 23.7935
25.0 0.0 25.0 1275.0 21.5801 17.6177 23.9341
26.0 0.0 26.0 1212.0 21.5859 17.5796 23.9165
29.0 0.0 29.0 1759.0 21.5625 17.5854 23.8726
46.0 0.0 46.0 4741.0 21.5215 17.6235 23.9458
⋮
2115.0 0.0 2115.0 1071.0 27.7705 13.2788 23.8081
2116.0 0.0 2116.0 839.0 27.7617 13.3081 23.8081
2117.0 0.0 2117.0 753.0 27.7793 13.2993 23.6851
2120.0 0.0 2120.0 866.0 27.7559 13.1792 23.8638
2125.0 0.0 2125.0 181.0 27.7939 13.0298 23.9194
2128.0 0.0 2128.0 296.0 27.791 13.0649 23.9019
2131.0 0.0 2131.0 323.0 28.3037 12.8188 23.9487
2132.0 0.0 2132.0 615.0 28.626 12.8188 23.8755
2137.0 0.0 2137.0 318.0 29.9736 15.0571 23.7202
2140.0 0.0 2140.0 1719.0 27.1436 15.6401 23.9048
2147.0 0.0 2147.0 1535.0 25.1953 9.93604 23.9897Load more than the found 12 columns from the header of the clump files. The order of the variables has to be consistent with the header in the clump files:
clumps = getclumps(info, vars=[ :index, :lev, :parent, :ncell, :peak_x, :peak_y, :peak_z, Symbol("rho-"), Symbol("rho+"), :rho_av, :mass_cl, :relevance, :vx, :vy, :vz]);[Mera]: Get clump data: 2025-06-30T00:02:32.938
domain:
xmin::xmax: 0.0 :: 1.0 ==> 0.0 [kpc] :: 48.0 [kpc]
ymin::ymax: 0.0 :: 1.0 ==> 0.0 [kpc] :: 48.0 [kpc]
zmin::zmax: 0.0 :: 1.0 ==> 0.0 [kpc] :: 48.0 [kpc]
Read 15 colums:
[:index, :lev, :parent, :ncell, :peak_x, :peak_y, :peak_z, Symbol("rho-"), Symbol("rho+"), :rho_av, :mass_cl, :relevance, :vx, :vy, :vz]
Memory used for data table :76.9365234375 KB
-------------------------------------------------------clumps.dataTable with 644 rows, 15 columns:
Columns:
# colname type
──────────────────────
1 index Float64
2 lev Float64
3 parent Float64
4 ncell Float64
5 peak_x Float64
6 peak_y Float64
7 peak_z Float64
8 rho- Float64
9 rho+ Float64
10 rho_av Float64
11 mass_cl Float64
12 relevance Float64
13 vx Float64
14 vy Float64
15 vz Float64Select Spatial Ranges
Use RAMSES Standard Notation
Ranges correspond to the domain [0:1]^3 and are related to the box corner at [0., 0., 0.] by default.
clumps = getclumps(info,
xrange=[0.2,0.8],
yrange=[0.2,0.8],
zrange=[0.4,0.6]); [Mera]: Get clump data: 2025-06-30T00:02:34.009
domain:
xmin::xmax: 0.2 :: 0.8 ==> 9.6 [kpc] :: 38.4 [kpc]
ymin::ymax: 0.2 :: 0.8 ==> 9.6 [kpc] :: 38.4 [kpc]
zmin::zmax: 0.4 :: 0.6 ==> 19.2 [kpc] :: 28.8 [kpc]
Read 12 colums:
[:index, :lev, :parent, :ncell, :peak_x, :peak_y, :peak_z, Symbol("rho-"), Symbol("rho+"), :rho_av, :mass_cl, :relevance]
Memory used for data table :61.58203125 KB
-------------------------------------------------------The loaded data ranges are assigned to the field ranges in an array in RAMSES standard notation (domain: [0:1]^3):
clumps.ranges6-element Vector{Float64}:
0.2
0.8
0.2
0.8
0.4
0.6Ranges relative to a given center:
clumps = getclumps(info,
xrange=[-0.3, 0.3],
yrange=[-0.3, 0.3],
zrange=[-0.1, 0.1],
center=[0.5, 0.5, 0.5]); [Mera]: Get clump data: 2025-06-30T00:02:35.986
center: [0.5, 0.5, 0.5] ==> [24.0 [kpc] :: 24.0 [kpc] :: 24.0 [kpc]]
domain:
xmin::xmax: 0.2 :: 0.8 ==> 9.6 [kpc] :: 38.4 [kpc]
ymin::ymax: 0.2 :: 0.8 ==> 9.6 [kpc] :: 38.4 [kpc]
zmin::zmax: 0.4 :: 0.6 ==> 19.2 [kpc] :: 28.8 [kpc]
Read 12 colums:
[:index, :lev, :parent, :ncell, :peak_x, :peak_y, :peak_z, Symbol("rho-"), Symbol("rho+"), :rho_av, :mass_cl, :relevance]
Memory used for data table :61.58203125 KB
-------------------------------------------------------Use notation in physical units
In the following example the ranges are given in units "kpc", relative to the box corner [0., 0., 0.] (default):
clumps = getclumps(info,
xrange=[2.,22.],
yrange=[2.,22.],
zrange=[22.,26.],
range_unit=:kpc); [Mera]: Get clump data: 2025-06-30T00:02:36.467
domain:
xmin::xmax: 0.0416667 :: 0.4583333 ==> 2.0 [kpc] :: 22.0 [kpc]
ymin::ymax: 0.0416667 :: 0.4583333 ==> 2.0 [kpc] :: 22.0 [kpc]
zmin::zmax: 0.4583333 :: 0.5416667 ==> 22.0 [kpc] :: 26.0 [kpc]
Read 12 colums:
[:index, :lev, :parent, :ncell, :peak_x, :peak_y, :peak_z, Symbol("rho-"), Symbol("rho+"), :rho_av, :mass_cl, :relevance]
Memory used for data table :12.64453125 KB
-------------------------------------------------------The possible physical length units for the keyword range_unit are defined in the field scale :
viewfields(info.scale) # or e.g.: clumps.info.scale[Mera]: Fields to scale from user/code units to selected units
=======================================================================
Mpc = 0.0010000000000006482
kpc = 1.0000000000006481
pc = 1000.0000000006482
mpc = 1.0000000000006482e6
ly = 3261.5637769461323
Au = 2.0626480623310105e23
km = 3.0856775812820004e16
m = 3.085677581282e19
cm = 3.085677581282e21
mm = 3.085677581282e22
μm = 3.085677581282e25
Mpc3 = 1.0000000000019446e-9
kpc3 = 1.0000000000019444
pc3 = 1.0000000000019448e9
mpc3 = 1.0000000000019446e18
ly3 = 3.469585750743794e10
Au3 = 8.775571306099254e69
km3 = 2.9379989454983075e49
m3 = 2.9379989454983063e58
cm3 = 2.9379989454983065e64
mm3 = 2.937998945498306e67
μm3 = 2.937998945498306e76
Msol_pc3 = 0.9997234790001649
Msun_pc3 = 0.9997234790001649
g_cm3 = 6.76838218451376e-23
Msol_pc2 = 999.7234790008131
Msun_pc2 = 999.7234790008131
g_cm2 = 0.20885045168302602
Gyr = 0.014910986463557083
Myr = 14.910986463557084
yr = 1.4910986463557083e7
s = 4.70554946422349e14
ms = 4.70554946422349e17
Msol = 9.99723479002109e8
Msun = 9.99723479002109e8
Mearth = 3.329677459032007e14
Mjupiter = 1.0476363431814971e12
g = 1.9885499720830952e42
km_s = 65.57528732282063
m_s = 65575.28732282063
cm_s = 6.557528732282063e6
nH = 30.987773856809987
erg = 8.551000140274429e55
g_cms2 = 2.9104844143584656e-9
T_mu = 517028.3199143136
K_mu = 517028.3199143136
T = 680300.4209398864
K = 680300.4209398864
Ba = 2.910484414358466e-9
g_cm_s2 = 2.910484414358466e-9
p_kB = 2.1080995598777838e7
K_cm3 = 2.1080995598777838e7Ranges relative to a given center e.g. in units "kpc":
clumps = getclumps(info,
xrange=[-16.,16.],
yrange=[-16.,16.],
zrange=[-2.,2.],
center=[24.,24.,24.],
range_unit=:kpc); [Mera]: Get clump data: 2025-06-30T00:02:36.917
center: [0.5, 0.5, 0.5] ==> [24.0 [kpc] :: 24.0 [kpc] :: 24.0 [kpc]]
domain:
xmin::xmax: 0.1666667 :: 0.8333333 ==> 8.0 [kpc] :: 40.0 [kpc]
ymin::ymax: 0.1666667 :: 0.8333333 ==> 8.0 [kpc] :: 40.0 [kpc]
zmin::zmax: 0.4583333 :: 0.5416667 ==> 22.0 [kpc] :: 26.0 [kpc]
Read 12 colums:
[:index, :lev, :parent, :ncell, :peak_x, :peak_y, :peak_z, Symbol("rho-"), Symbol("rho+"), :rho_av, :mass_cl, :relevance]
Memory used for data table :61.58203125 KB
-------------------------------------------------------Use the short notation for the box center :bc or :boxcenter for all dimensions (x,y,z):
clumps = getclumps(info,
xrange=[-16.,16.],
yrange=[-16.,16.],
zrange=[-2.,2.],
center=[:boxcenter],
range_unit=:kpc); [Mera]: Get clump data: 2025-06-30T00:02:37.349
center: [0.5, 0.5, 0.5] ==> [24.0 [kpc] :: 24.0 [kpc] :: 24.0 [kpc]]
domain:
xmin::xmax: 0.1666667 :: 0.8333333 ==> 8.0 [kpc] :: 40.0 [kpc]
ymin::ymax: 0.1666667 :: 0.8333333 ==> 8.0 [kpc] :: 40.0 [kpc]
zmin::zmax: 0.4583333 :: 0.5416667 ==> 22.0 [kpc] :: 26.0 [kpc]
Read 12 colums:
[:index, :lev, :parent, :ncell, :peak_x, :peak_y, :peak_z, Symbol("rho-"), Symbol("rho+"), :rho_av, :mass_cl, :relevance]
Memory used for data table :61.58203125 KB
-------------------------------------------------------clumps = getclumps(info,
xrange=[-16.,16.],
yrange=[-16.,16.],
zrange=[-2.,2.],
center=[:bc],
range_unit=:kpc); [Mera]: Get clump data: 2025-06-30T00:02:37.926
center: [0.5, 0.5, 0.5] ==> [24.0 [kpc] :: 24.0 [kpc] :: 24.0 [kpc]]
domain:
xmin::xmax: 0.1666667 :: 0.8333333 ==> 8.0 [kpc] :: 40.0 [kpc]
ymin::ymax: 0.1666667 :: 0.8333333 ==> 8.0 [kpc] :: 40.0 [kpc]
zmin::zmax: 0.4583333 :: 0.5416667 ==> 22.0 [kpc] :: 26.0 [kpc]
Read 12 colums:
[:index, :lev, :parent, :ncell, :peak_x, :peak_y, :peak_z, Symbol("rho-"), Symbol("rho+"), :rho_av, :mass_cl, :relevance]
Memory used for data table :61.58203125 KB
-------------------------------------------------------Use the box center notation for individual dimensions, here x,z:
clumps = getclumps(info,
xrange=[-16.,16.],
yrange=[-16.,16.],
zrange=[-2.,2.],
center=[:bc, 24., :bc],
range_unit=:kpc); [Mera]: Get clump data: 2025-06-30T00:02:38.364
center: [0.5, 0.5, 0.5] ==> [24.0 [kpc] :: 24.0 [kpc] :: 24.0 [kpc]]
domain:
xmin::xmax: 0.1666667 :: 0.8333333 ==> 8.0 [kpc] :: 40.0 [kpc]
ymin::ymax: 0.1666667 :: 0.8333333 ==> 8.0 [kpc] :: 40.0 [kpc]
zmin::zmax: 0.4583333 :: 0.5416667 ==> 22.0 [kpc] :: 26.0 [kpc]
Read 12 colums:
[:index, :lev, :parent, :ncell, :peak_x, :peak_y, :peak_z, Symbol("rho-"), Symbol("rho+"), :rho_av, :mass_cl, :relevance]
Memory used for data table :61.58203125 KB
-------------------------------------------------------