def dm_exponential_dip(tmin, tmax, idx=2, sign='negative', name='dmexp'):
"""
Returns chromatic exponential dip (i.e. TOA advance):
:param tmin, tmax:
search window for exponential dip time.
:param idx:
index of radio frequency dependence (i.e. DM is 2). If this is set
to 'vary' then the index will vary from 1 - 6
:param sign:
set sign of dip: 'positive', 'negative', or 'vary'
:param name: Name of signal
:return dmexp:
chromatic exponential dip waveform.
"""
t0_dmexp = parameter.Uniform(tmin, tmax)
log10_Amp_dmexp = parameter.Uniform(-10, -2)
log10_tau_dmexp = parameter.Uniform(0, 2.5)
if sign == 'vary':
sign_param = parameter.Uniform(-1.0, 1.0)
elif sign == 'positive':
sign_param = 1.0
else:
sign_param = -1.0
wf = chrom_exp_decay(log10_Amp=log10_Amp_dmexp,
t0=t0_dmexp,
log10_tau=log10_tau_dmexp,
sign_param=sign_param,
idx=idx)
dmexp = deterministic_signals.Deterministic(wf, name=name)
return dmexp
def dm_exponential_dip(tmin, tmax, idx=2, sign='negative', name='dmexp',
lgA_min=-10., lgA_max=-5., sign_min=-1., sign_max=1.,
tau_min_10_pow=5, tau_max_10_pow=100):
t0_dmexp = parameter.Uniform(tmin,tmax)
log10_Amp_dmexp = parameter.Uniform(lgA_min, lgA_max)
log10_tau_dmexp = parameter.Uniform(np.log10(tau_min_10_pow),
np.log10(tau_max_10_pow))
if idx=='vary':
idx = parameter.Uniform(-7, 7)
if sign == 'vary':
sign_param = parameter.Uniform(sign_min, sign_max)
elif sign == 'positive':
sign_param = 1.0
else:
sign_param = -1.0
wf = chromatic.chrom_exp_decay(log10_Amp=log10_Amp_dmexp,
t0=t0_dmexp, log10_tau=log10_tau_dmexp,
sign_param=sign_param, idx=idx)
dmexp = deterministic_signals.Deterministic(wf, name=name)
return dmexp