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zblz / naima

Derivation of non-thermal particle distributions through MCMC spectral fitting
http://naima.readthedocs.io
BSD 3-Clause "New" or "Revised" License
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Got error: ValueError: Number of samples, -22, must be non-negative. #228

Open Jongsu020509 opened 10 months ago

Jongsu020509 commented 10 months ago

I hope this message finds you well.

I have developed a code using the Syn and IC model, utilizing X-ray and Gamma-ray data. The code structure is as follows:

def ElectronSynIC(pars, data): amplitude = pars[0] / u.eV alpha = pars[1] E0 = 1 u.TeV dist = 4.5 u.kpc Bemi_unit = pars[2] * u.uG Emax = 10*pars[3] u.TeV Emin = 10*pars[4] u.MeV

PL = PowerLaw(amplitude, E0, alpha)
IC = InverseCompton(PL, seed_photon_fields=[
    ['MBR', 2.725*u.K, 0.261*u.eV/u.cm**3], 
    'FIR', 'NIR'],
    Eemax=Emax, Eemin=Emin)
SYN = Synchrotron(PL, B=Bemi_unit, Eemax=Emax, Eemin=Emin)
model = IC.flux(data, distance=dist).to(data["flux"].unit) + SYN.flux(data, distance=dist).to(data["flux"].unit)
return model

def lnprior(pars): logprob = ( naima.uniform_prior(pars[0], 0.0, np.inf)

if name == "main": p0 = np.array((1.e33, 3., 30, 1.0, 2.5)) labels = ["norm", "alpha", "Bsh", "Emax", "Emin"] sampler, pos = naima.run_sampler( data_table=[xray, vhe1, vhe2], p0=p0, labels=labels, model=ElectronSynIC, prior=lnprior, nwalkers=10, nburn=50, nrun=5000, threads=8, prefit=True, interactive=False )

While running the code, I encountered the following error:

ValueError: Number of samples, -22, must be non-negative.

In a previous inquiry, it was suggested that the issue might be related to Emin and Emax. However, based on my analysis, it seems that the prior ranges for Emin and Emax do not overlap. Could you please assist me in identifying the source of the problem? Is it related to the energy settings or could there be another underlying issue?

I greatly appreciate your expertise and assistance in resolving this matter. Your guidance would be immensely valuable to me.

Thank you for your time and consideration.

zblz commented 10 months ago

Can you provide the full traceback of the error?

Jongsu020509 commented 10 months ago

Hi,

Here is the full trackbase of the error:

Traceback (most recent call last):

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/multiprocessing/pool.py", line 125, in worker

result = (True, func(*args, **kwds))

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/multiprocessing/pool.py", line 48, in mapstar

return list(map(*args))

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/site-packages/emcee/ensemble.py", line 624, in call

return self.f(x, *self.args, **self.kwargs)

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/site-packages/naima/core.py", line 109, in lnprob

modelout = modelfunc(pars, data)

File "/Users/jongsulee/Work/python_code/CTA_New_CODE/GC_diffuse/NGC6397/test/SynIC_PL_Bsh_00.py", line 42, in ElectronSynIC

model = IC.flux(data, distance=dist).to(data["flux"].unit) +

SYN.flux(data, distance=dist).to(data["flux"].unit)

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/site-packages/naima/radiative.py", line 771, in flux

model = super().flux(photon_energy, distance=distance)

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/site-packages/naima/model_utils.py", line 63, in model

result = func(cls, energy, *args, **kwargs)

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/site-packages/naima/radiative.py", line 101, in flux

spec = self._spectrum(photon_energy)

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/site-packages/naima/radiative.py", line 748, in _spectrum

self._calc_specic(seed, outspecene).to("1/(s eV)")

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/site-packages/naima/radiative.py", line 705, in _calc_specic

self._gam, T.to("K").value, Eph

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/site-packages/naima/radiative.py", line 155, in _gam

return np.logspace(

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/site-packages/numpy/core/function_base.py", line 295, in logspace

y = linspace(start, stop, num=num, endpoint=endpoint, axis=axis)

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/site-packages/numpy/core/function_base.py", line 124, in linspace

raise ValueError("Number of samples, %s, must be non-negative." % num)

ValueError: Number of samples, -11, must be non-negative.

"""

The above exception was the direct cause of the following exception:

Traceback (most recent call last):

File "/Users/jongsulee/Work/python_code/CTA_New_CODE/GC_diffuse/NGC6397/test/SynIC_PL_Bsh_00.py", line 72, in 

sampler, pos = naima.run_sampler(

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/site-packages/naima/core.py", line 551, in run_sampler

sampler, pos = _run_mcmc(sampler, pos, nrun)

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/site-packages/naima/core.py", line 134, in _run_mcmc

for i, state in enumerate(

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/site-packages/emcee/ensemble.py", line 402, in sample

state, accepted = move.propose(model, state)

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/site-packages/emcee/moves/red_blue.py", line 93, in propose

new_log_probs, new_blobs = model.compute_log_prob_fn(q)

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/site-packages/emcee/ensemble.py", line 489, in compute_log_prob

results = list(map_func(self.log_prob_fn, p))

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/multiprocessing/pool.py", line 367, in map

return self._map_async(func, iterable, mapstar, chunksize).get()

File "/Users/jongsulee/miniforge3/envs/naima/lib/python3.10/multiprocessing/pool.py", line 774, in get

raise self._value

ValueError: Number of samples, -11, must be non-negative.

Sometimes, my code ends up completely successful. In the case of nwalker=10, and nrum=1000. nrun=100 succeeds relatively often.

Thanks for your reply.

Best Regards, Jongsu

2023년 8월 23일 (수) 오전 1:34, Víctor Zabalza @.***>님이 작성:

Can you provide the full traceback of the error?

— Reply to this email directly, view it on GitHub https://github.com/zblz/naima/issues/228#issuecomment-1688551863, or unsubscribe https://github.com/notifications/unsubscribe-auth/APS4AHTMFS3AM3TPUMQ2IL3XWTNQBANCNFSM6AAAAAA3XGX6RU . You are receiving this because you authored the thread.Message ID: @.***>