CONCEPT (COsmological N-body CodE in PyThon) is a free and open-source simulation code for cosmological structure formation

Hi Jeppe,

I tried bash <(wget -O- https://raw.githubusercontent.com/jmd-dk/concept/${concept_version}/install), as a result, it removes other packages in the directory where I tried to install concept, if I didn't do something wrong. I think it is necessary to note that in the documentation.

Thanks! Zhejie

Hi! First of all great program, it was a breeze to install. I have one question/issue I would like to ask regarding the importance of Cosmology parameters in the simulation. I tried changing around Ωcdm, Ωb and H0 to see the variation in the simulation. However, after doing so and saving snapshots at many different times for each simulation I noticed that the simulations are very similar in their renders and even plotting them (using scatter) they are almost the same even with wildly different parameters. Is this expected behavior? For reference here are two screenshots of simulations at a=0.3877 with the first picture as parameters:

H0 = 67km/(sMpc) Ωcdm = 0.27 Ωb = 0.049

and the second:

H0 = 90km/(sMpc) Ωcdm = 0.46 Ωb = 0.049 a_begin = 0.05

I made a param file and ran it with concept but it returns me a invalid syntax of render2D like follow: Traceback (most recent call last): File "", line 5, in File "/home/user/test/disk/concept/dep/python/lib/python3.9/ast.py", line 50, in parse return compile(source, filename, mode, flags, File "", line 8 'render2D': a_begin ^ SyntaxError: invalid syntax An error occurred! I learned the tutorial and tired to modify the code but still can't work,and here's my code: initial_conditions = { 'species': 'matter', 'N' : 64**3, }

output_times = { 'snapshot': a_begin 'render2D': a_begin } output_dirs = { 'snapshot': path.output_dir 'render2D': path.output_dir }

render2D_select = { 'all': { 'data' : False, 'image' : True, 'terminal image': True, }, }

snapshot_select = { 'save': { 'matter': { 'pos': True, 'mom': True, 'J' : True, }, }, 'load': { 'matter': { 'pos': True, 'mom': True, 'J' : True, }, }, } snapshot_type = 'concept'

boxsize = 256*Mpc/h potential_options = 128

H0 = 67km/(sMpc) Ωb = 0.049 Ωcdm = 0.27 a_begin = 0.02 primordial_spectrum = { 'A_s': 2.1e-9, # Amplitude 'n_s': 0.96, # Tilt / spectral index }

When run with the following content of the param-file:

# Non-parameter variable used to control the size of the simulation
_size = 128

# Input/output
initial_conditions = {
    'species': 'matter',
    'N'      : _size**3,
}
output_dirs = {
    'render2D' : paths['output_dir']
}
output_times = {
    'render2D' : logspace(log10(a_begin), log10(1), 100)
}
render2D_select = {
    'matter': {'data': False, 'image': True,  'terminal image': False},
}

# Numerical parameters
boxsize = 128*Mpc

# Cosmology
H0      = 67*km/(s*Mpc)
Ωcdm    = 0.27
Ωb      = 0.049
a_begin = 0.02

# Physics
select_forces = {
    'matter': {'gravity': ('pm', 2*_size)},
}

# Graphics
render2D_options = {
    'gridsize': {
        'matter': _size,
    },
    'terminal resolution': {
        'matter': 80,
    },
    'colormap': {
        'matter': 'inferno',
    },
}

concept produces the following error message instead of rendering the 2D image:

Traceback (most recent call last):
  File "graphics.pyx", line 568, in graphics.render2D
    BEGIN_UNICODE__DOUBLE__DASH__STRUCK__SPACE__CAPITAL__SPACE__R__END_UNICODE_237__DIV____LTH__double__GTH____OPAR__vmax_terminal__MIN__vmin_terminal__CPAR__ = <double>(237/<double>(vmax_terminal - vmin_terminal))
UnboundLocalError: local variable 'vmax_terminal' referenced before assignment
Exception ignored in: 'main.dump'
Traceback (most recent call last):
  File "graphics.pyx", line 568, in graphics.render2D
    BEGIN_UNICODE__DOUBLE__DASH__STRUCK__SPACE__CAPITAL__SPACE__R__END_UNICODE_237__DIV____LTH__double__GTH____OPAR__vmax_terminal__MIN__vmin_terminal__CPAR__ = <double>(237/<double>(vmax_terminal - vmin_terminal))
UnboundLocalError: local variable 'vmax_terminal' referenced before assignment

When run with 'terminal image': True it completes successfully.