本文整理汇总了Python中classy.Class.get_background方法的典型用法代码示例。如果您正苦于以下问题：Python Class.get_background方法的具体用法？Python Class.get_background怎么用？Python Class.get_background使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类classy.Class的用法示例。
在下文中一共展示了Class.get_background方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: len
# 需要导入模块: from classy import Class [as 别名]
# 或者: from classy.Class import get_background [as 别名]
# define conformal time sampling array
#
times = M.get_current_derived_parameters(['tau_rec','conformal_age'])
tau_rec=times['tau_rec']
tau_0 = times['conformal_age']
tau1 = np.logspace(math.log10(tau_ini),math.log10(tau_rec),tau_num_early)
tau2 = np.logspace(math.log10(tau_rec),math.log10(tau_0),tau_num_late)[1:]
tau2[-1] *= 0.999 # this tiny shift avoids interpolation errors
tau = np.concatenate((tau1,tau2))
tau_num = len(tau)
#
# use table of background and thermodynamics quantitites to define some functions
# returning some characteristic scales
# (of Hubble crossing, sound horizon crossing, etc.) at different time
#
background = M.get_background() # load background table
#print background.viewkeys()
thermodynamics = M.get_thermodynamics() # load thermodynamics table
#print thermodynamics.viewkeys()
#
background_tau = background['conf. time [Mpc]'] # read conformal times in background table
background_z = background['z'] # read redshift
background_aH = 2.*math.pi*background['H [1/Mpc]']/(1.+background['z'])/M.h() # read 2pi * aH in [h/Mpc]
background_ks = 2.*math.pi/background['comov.snd.hrz.']/M.h() # read 2pi/(comoving sound horizon) in [h/Mpc]
background_rho_m_over_r = (background['(.)rho_b']+background['(.)rho_cdm']) /(background['(.)rho_g']+background['(.)rho_ur']) # read rho_r / rho_m (to find time of equality)
background_rho_l_over_m = background['(.)rho_lambda'] /(background['(.)rho_b']+background['(.)rho_cdm']) # read rho_m / rho_lambda (to find time of equality)
thermodynamics_tau = thermodynamics['conf. time [Mpc]'] # read confromal times in thermodynamics table
thermodynamics_kd = 2.*math.pi/thermodynamics['r_d']/M.h() # read 2pi(comoving diffusion scale) in [h/Mpc]
#
# define a bunch of interpolation functions based on previous quantities
#示例2: Class
# 需要导入模块: from classy import Class [as 别名]
# 或者: from classy.Class import get_background [as 别名]
#Einstein-de Sitter
CDM = Class()
CDM.set({'Omega_cdm':0.95,'Omega_b':0.05})
CDM.compute()
# Just to cross-check that Omega_Lambda is negligible
# (but not exactly zero because we neglected radiation)
derived = CDM.get_current_derived_parameters(['Omega0_lambda'])
print derived
print "Omega_Lambda =",derived['Omega0_lambda']
# In[ ]:
#Get background quantities and recover their names:
baLCDM = LCDM.get_background()
baCDM = CDM.get_background()
baCDM.viewkeys()
# In[ ]:
#Get H_0 in order to plot the distances in this unit
fLCDM = LCDM.Hubble(0)
fCDM = CDM.Hubble(0)
# In[ ]:
namelist = ['lum. dist.','comov. dist.','ang.diam.dist.']
colours = ['b','g','r']