Get a RAMSES output into PyMSES

Use case

You want to select a specific RAMSES output directory and get somme basic information about it

RAMSES output selection

First, you need to select the snapshot of your RAMSES simulation you would like to read by creating a RamsesOutput object :

import pymses
ro = pymses.RamsesOutput("/data/Aquarius/outputs", 193)

In this example, you are intersted in the files contained in /data/Aquarius/output/ouput_00193/

Ouput information

To get some details about this specific output/simulation. Everything you need is in the info parameter :

ro.info
Out:{'H0': 73.0,
    'aexp': 1.0000620502295701,
    'boxlen': 1.0,
    'dom_decomp': <pymses.sources.ramses.hilbert.HilbertDomainDecomp object at 0x3305e10>,
    'levelmax': 18,
    'levelmin': 7,
    'ncpu': 64,
    'ndim': 3,
    'ngridmax': 800000,
    'nstep_coarse': 9578,
    'omega_b': 0.039999999105930301,
    'omega_k': 0.0,
    'omega_l': 0.75,
    'omega_m': 0.25,
    'time': 6.2446534480863097e-05,
    'unit_density': (2.50416381926e-27 m^-3.kg),
    'unit_length': (4.21943976727e+24 m),
    'unit_mass': (1.88116596007e+47 kg),
    'unit_pressure': (2.50385294276e-13 m^-1.kg.s^-2),
    'unit_temperature': (12021826243.9 K),
    'unit_time': (4.21970170037e+17 s),
    'unit_velocity': (9999379.26156 m.s^-1)}

ro.info["ncpu"]
Out:64

ro.info["boxlen"] / 2**ro.info["levelmax"]
Out:3.814697265625e-06

This way, you can easily find the units of your data (see Dealing with units).