How to select list of components

When you instantiate CunsIn(simname, select_c ,select_t,verbose) object, you can specify one or many components separated by "," from the list below:

gas, disk, halo, dm, stars, bulge, bndry, all

component value description
gas Gas particles
halo Dark matter particles
dm Dark matter particles
disk Old stars particles
stars Stars particles
bulge Bulge particles
bndry bndry particles

  • to select gas only
  • to select halo and gas and stars
  • to select all components

How to select list of ranges of particles

When you instantiate uns::UnsIn(simname, select_c ,select_t,verbose) object, you can specify one or many range of particles separated by "," . This is useful for nbody simulations file format which don't have components like NEMO format.

  • to select particle in one range 0:99999
  • to select particles from 2 ranges 0:99999 and 300000:399999
  • to select all particles

How to specify range of time at loading

When you instantiate uns::UnsIn(simname, select_c, select_t ,verbose) object, you can specify only a sequence of time step to load. Range of time is controlled by a string variable with the following syntax:

  • select_t="5.0"
    will load time step 5.0
  • select_t="0.0:3.0"
    will load all time steps between time from 0.0 to 3.0
  • select_t="0.0:3.0,5.0:7.0"
    will load all time steps between time from 0.0 to 3.0 and from 5.0 to 7.0

How to select data at loading

When you load a snapshot by calling method snapshot->nextFrame(bits), you can give a parameter 'bits', to specify which data you want to load. A user may not want to load all the possible data stored in a snapshot but just few of them. This feature can dramatically speed up file reading in case of big input files.

Variable bits is a c++ string, or a char * composed of letters which represent data that user may want to load. Here is the list of all available data.

character description
x position
v velocity
m mass
p potential
a acceleration
R density
H hsml
I particles id
e softening
U internal energy
M metallicity
A stars age
T temperature
k keys (nemo)
X auxiliary (nemo)
z extra 1
Z extra 2
i extra 3
  • bits="xvm"
    load positions, velocities and masses
  • bits="xRH"
    load positions, densities and hsml
  • bit=""
    load all data (default)