def period_search_ls(t, mag, magerr, remove_harmonics=True):
ls = LombScargleFast(silence_warnings=True)
T = np.max(t) - np.min(t)
ls.optimizer.period_range = (0.01, T)
ls.fit(t, mag, magerr)
period = ls.best_period
power = ls.periodogram(period)
# https://github.com/astroML/gatspy/blob/master/examples/FastLombScargle.ipynb
oversampling = 3.0
N = len(t)
df = 1. / (oversampling * T) # frequency grid spacing
fmin = 2 / T
fmax = 480 # minimum period is 0.05 d
Nf = (fmax - fmin) // df
freqs = fmin + df * np.arange(Nf)
periods = 1 / freqs
powers = ls._score_frequency_grid(fmin, df, Nf)
ind_best = np.argsort(powers)[-1]
period = periods[ind_best]
power = powers[ind_best]
# calcualte false alarm probability (FAP)
Z = power
normalization = 'standard'
# fap_Neff is underestimate
fap_Neff = FAP_estimated(Z, N, fmax, t, normalization=normalization)
"""
# fap_Baluev is overestimate
fap_Baluev = FAP_aliasfree(Z, N, fmax, t, mag, magerr, normalization=normalization)
"""
psigma = (np.percentile(powers, 84) - np.percentile(powers, 16)) / 2
significance = power / psigma
if remove_harmonics == True:
# In some cases, the period search is not successful:
harmonics = np.array([1 / 5, 1 / 4, 1 / 3, 1 / 2, 1., 2.])
if abs(period - T) < 0.005:
period = -99
else:
for harmonic in harmonics:
if abs(period - harmonic) < 0.005:
if fap_Neff > 0.001:
period = -99
data_out = {}
data_out["period"] = period
data_out["significance"] = significance
data_out["freqs"] = freqs
data_out["powers"] = powers
data_out["power"] = power
data_out["Nztfobs"] = N
data_out["fap_Neff"] = fap_Neff
# data_out["fap_Baluev"] = fap_Baluev
return data_out
def find_cycle(feature,
strain,
mouse=None,
bin_width=15,
methods='LombScargleFast',
disturb_t=False,
gen_doc=False,
plot=True,
search_range_fit=None,
nyquist_factor=3,
n_cycle=10,
search_range_find=(2, 26),
sig=np.array([0.05])):
"""
Use Lomb-Scargel method on different strain and mouse's data to find the
best possible periods with highest p-values. The function can be used on
specific strains and specific mouses, as well as just specific strains
without specifying mouse number. We use the O(NlogN) fast implementation
of Lomb-Scargle from the gatspy package, and also provide a way to
visualize the result.
Note that either plotting or calculating L-S power doesn't use the same
method in finding best cycle. The former can use user-specified
search_range, while the latter uses default two grid search_range.
Parameters
----------
feature: string in {"AS", "F", "M_AS", "M_IS", "W", "Distance"}
"AS": Active state probalibity
"F": Food consumed (g)
"M_AS": Movement outside homebase
"M_IS": Movement inside homebase
"W": Water consumed (g)
"Distance": Distance traveled
strain: int
nonnegative integer indicating the strain number
mouse: int, default is None
nonnegative integer indicating the mouse number
bin_width: int, minute unit, default is 15 minutes
number of minutes, the time interval for data aggregation
methods: string in {"LombScargleFast", "LombScargle"}
indicating the method used in determining periods and best cycle.
If choose 'LombScargle', 'disturb_t' must be True.
disturb_t: boolean, default is False
If True, add uniformly distributed noise to the time sequence which
are used to fit the Lomb Scargle model. This is to avoid the singular
matrix error that could happen sometimes.
plot: boolean, default is True
If True, call the visualization function to plot the Lomb Scargle
power versus periods plot. First use the data (either strain specific
or strain-mouse specific) to fit the LS model, then use the
search_range_fit as time sequence to predict the corresponding LS
power, at last draw the plot out. There will also be stars and
horizontal lines indicating the p-value of significance. Three stars
will be p-value in [0,0.001], two stars will be p-value in
[0.001,0.01], one star will be p-value in [0.01,0.05]. The horizontal
line is the LS power that has p-value of 0.05.
search_range_fit: list, numpy array or numpy arange, hours unit,
default is None
list of numbers as the time sequence to predict the corrsponding
Lomb Scargle power. If plot is 'True', these will be drawn as the
x-axis. Note that the number of search_range_fit points can not be
too small, or the prediction smooth line will not be accurate.
However the plot will always give the right periods and their LS
power with 1,2 or 3 stars. This could be a sign to check whether
search_range_fit is not enough to draw the correct plot.
We recommend the default None, which is easy to use.
nyquist_factor: int
If search_range_fit is None, the algorithm will automatically
choose the periods sequence.
5 * nyquist_factor * length(time sequence) / 2 gives the number of
power and periods used to make LS prediction and plot the graph.
n_cycle: int, default is 10
numbers of periods to be returned by function, which have the highest
Lomb Scargle power and p-value.
search_range_find: list, tuple or numpy array with length of 2, default is
(2,26), hours unit
Range of periods to be searched for best cycle. Note that the minimum
should be strictly larger than 0 to avoid 1/0 issues.
sig: list or numpy array, default is [0.05].
significance level to be used for plot horizontal line.
gen_doc: boolean, default is False
If true, return the parameters needed for visualize the LS power versus
periods
Returns
-------
cycle: numpy array of length 'n_cycle'
The best periods with highest LS power and p-values.
cycle_power: numpy array of length 'n_cycle'
The corrsponding LS power of 'cycle'.
cycle_pvalue: numpy array of length 'n_cycle'
The corrsponding p-value of 'cycle'.
periods: numpy array of the same length with 'power'
use as time sequence in LS model to make predictions.Only return when
gen_doc is True.
power: numpy array of the same length with 'periods'
the corresponding predicted power of periods. Only return when
gen_doc is True.
sig: list, tuple or numpy array, default is [0.05].
significance level to be used for plot horizontal line.
Only return when gen_doc is True.
N: int
the length of time sequence in the fit model. Only return when
gen_doc is True.
Examples
-------
>>> a,b,c = find_cycle(feature='F', strain = 0,mouse = 0, plot=False,)
>>> print(a,b,c)
>>> [ 23.98055016 4.81080233 12.00693952 6.01216335 8.0356203
3.4316698 2.56303353 4.9294791 21.37925713 3.5697756 ]
[ 0.11543449 0.05138839 0.03853218 0.02982237 0.02275952
0.0147941 0.01151601 0.00998443 0.00845883 0.0082382 ]
[ 0.00000000e+00 3.29976046e-10 5.39367189e-07 8.10528027e-05
4.71001953e-03 3.70178834e-01 9.52707020e-01 9.99372657e-01
9.99999981e-01 9.99999998e-01]
"""
if feature not in ALL_FEATURES:
raise ValueError(
'Input value must in {"AS", "F", "M_AS", "M_IS", "W", "Distance"}')
if methods not in METHOD:
raise ValueError(
'Input value must in {"LombScargleFast","LombScargle"}')
# get data
if mouse is None:
data_all = aggregate_data(feature=feature, bin_width=bin_width)
n_mouse_in_strain = len(
set(data_all.loc[data_all['strain'] == strain]['mouse']))
data = [[] for i in range(n_mouse_in_strain)]
t = [[] for i in range(n_mouse_in_strain)]
for i in range(n_mouse_in_strain):
data[i] = data_all.loc[(data_all['strain'] == strain)
& (data_all['mouse'] == i)][feature]
t[i] = np.array(
np.arange(0,
len(data[i]) * bin_width / 60, bin_width / 60))
data = [val for sublist in data for val in sublist]
N = len(data)
t = [val for sublist in t for val in sublist]
else:
if feature == 'Distance':
data = aggregate_movement(strain=strain,
mouse=mouse,
bin_width=bin_width)
N = len(data)
t = np.arange(0, N * bin_width / 60, bin_width / 60)
else:
data = aggregate_interval(strain=strain,
mouse=mouse,
feature=feature,
bin_width=bin_width)
N = len(data)
t = np.arange(0, N * bin_width / 60, bin_width / 60)
y = data
# fit model
if disturb_t is True:
t = t + np.random.uniform(-bin_width / 600, bin_width / 600, N)
if methods == 'LombScargleFast':
model = LombScargleFast(fit_period=False).fit(t=t, y=y)
elif methods == 'LombScargle':
model = LombScargle(fit_period=False).fit(t=t, y=y)
# calculate periods' LS power
if search_range_fit is None:
periods, power = model.periodogram_auto(nyquist_factor=nyquist_factor)
else:
periods = search_range_fit
power = model.periodogram(periods=search_range_fit)
# find best cycle
model.optimizer.period_range = search_range_find
cycle, cycle_power = model.find_best_periods(return_scores=True,
n_periods=n_cycle)
cycle_pvalue = 1 - (1 - np.exp(cycle_power / (-2) * (N - 1)))**(2 * N)
# visualization
if plot is True:
lombscargle_visualize(periods=periods,
power=power,
sig=sig,
N=N,
cycle_power=cycle_power,
cycle_pvalue=cycle_pvalue,
cycle=cycle)
if gen_doc is True:
return periods, power, sig, N, cycle, cycle_power, cycle_pvalue
return cycle, cycle_power, cycle_pvalue
period = periods[np.argmax(periodogram)] extra = '' ################################################################################ ################################################################################ # Conditional entropy (adaptive grid) ################################################################################ elif options.algorithm == 'ce-adaptive': from ce import ConditionalEntropy starttime = datetime.now() model = ConditionalEntropy(t, m, verbose = True) periods, periodogram = model.periodogram() period = model.best_periods[0] endtime = datetime.now() print 'Periods: ' + str(model.best_periods) print 'Scores: ' + str(model.best_scores) extra = '' ################################################################################ ################################################################################ # Conditional entropy ################################################################################ elif options.algorithm == 'ce':
period = periods[np.argmax(periodogram)]
extra = ''
################################################################################
################################################################################
# Conditional entropy (adaptive grid)
################################################################################
elif options.algorithm == 'ce-adaptive':
from ce import ConditionalEntropy
starttime = datetime.now()
model = ConditionalEntropy(t, m, verbose=True)
periods, periodogram = model.periodogram()
period = model.best_periods[0]
endtime = datetime.now()
print 'Periods: ' + str(model.best_periods)
print 'Scores: ' + str(model.best_scores)
extra = ''
################################################################################
################################################################################
# Conditional entropy
################################################################################
elif options.algorithm == 'ce':
def find_cycle(feature, strain, mouse=None, bin_width=15,
methods='LombScargleFast', disturb_t=False, gen_doc=False,
plot=True, search_range_fit=None, nyquist_factor=3,
n_cycle=10, search_range_find=(2, 26), sig=np.array([0.05])):
"""
Use Lomb-Scargel method on different strain and mouse's data to find the
best possible periods with highest p-values. The function can be used on
specific strains and specific mouses, as well as just specific strains
without specifying mouse number. We use the O(NlogN) fast implementation
of Lomb-Scargle from the gatspy package, and also provide a way to
visualize the result.
Note that either plotting or calculating L-S power doesn't use the same
method in finding best cycle. The former can use user-specified
search_range, while the latter uses default two grid search_range.
Parameters
----------
feature: string in {"AS", "F", "M_AS", "M_IS", "W", "Distance"}
"AS": Active state probalibity
"F": Food consumed (g)
"M_AS": Movement outside homebase
"M_IS": Movement inside homebase
"W": Water consumed (g)
"Distance": Distance traveled
strain: int
nonnegative integer indicating the strain number
mouse: int, default is None
nonnegative integer indicating the mouse number
bin_width: int, minute unit, default is 15 minutes
number of minutes, the time interval for data aggregation
methods: string in {"LombScargleFast", "LombScargle"}
indicating the method used in determining periods and best cycle.
If choose 'LombScargle', 'disturb_t' must be True.
disturb_t: boolean, default is False
If True, add uniformly distributed noise to the time sequence which
are used to fit the Lomb Scargle model. This is to avoid the singular
matrix error that could happen sometimes.
plot: boolean, default is True
If True, call the visualization function to plot the Lomb Scargle
power versus periods plot. First use the data (either strain specific
or strain-mouse specific) to fit the LS model, then use the
search_range_fit as time sequence to predict the corresponding LS
power, at last draw the plot out. There will also be stars and
horizontal lines indicating the p-value of significance. Three stars
will be p-value in [0,0.001], two stars will be p-value in
[0.001,0.01], one star will be p-value in [0.01,0.05]. The horizontal
line is the LS power that has p-value of 0.05.
search_range_fit: list, numpy array or numpy arange, hours unit,
default is None
list of numbers as the time sequence to predict the corrsponding
Lomb Scargle power. If plot is 'True', these will be drawn as the
x-axis. Note that the number of search_range_fit points can not be
too small, or the prediction smooth line will not be accurate.
However the plot will always give the right periods and their LS
power with 1,2 or 3 stars. This could be a sign to check whether
search_range_fit is not enough to draw the correct plot.
We recommend the default None, which is easy to use.
nyquist_factor: int
If search_range_fit is None, the algorithm will automatically
choose the periods sequence.
5 * nyquist_factor * length(time sequence) / 2 gives the number of
power and periods used to make LS prediction and plot the graph.
n_cycle: int, default is 10
numbers of periods to be returned by function, which have the highest
Lomb Scargle power and p-value.
search_range_find: list, tuple or numpy array with length of 2, default is
(2,26), hours unit
Range of periods to be searched for best cycle. Note that the minimum
should be strictly larger than 0 to avoid 1/0 issues.
sig: list or numpy array, default is [0.05].
significance level to be used for plot horizontal line.
gen_doc: boolean, default is False
If true, return the parameters needed for visualize the LS power versus
periods
Returns
-------
cycle: numpy array of length 'n_cycle'
The best periods with highest LS power and p-values.
cycle_power: numpy array of length 'n_cycle'
The corrsponding LS power of 'cycle'.
cycle_pvalue: numpy array of length 'n_cycle'
The corrsponding p-value of 'cycle'.
periods: numpy array of the same length with 'power'
use as time sequence in LS model to make predictions.Only return when
gen_doc is True.
power: numpy array of the same length with 'periods'
the corresponding predicted power of periods. Only return when
gen_doc is True.
sig: list, tuple or numpy array, default is [0.05].
significance level to be used for plot horizontal line.
Only return when gen_doc is True.
N: int
the length of time sequence in the fit model. Only return when
gen_doc is True.
Examples
-------
>>> a,b,c = find_cycle(feature='F', strain = 0,mouse = 0, plot=False,)
>>> print(a,b,c)
>>> [ 23.98055016 4.81080233 12.00693952 6.01216335 8.0356203
3.4316698 2.56303353 4.9294791 21.37925713 3.5697756 ]
[ 0.11543449 0.05138839 0.03853218 0.02982237 0.02275952
0.0147941 0.01151601 0.00998443 0.00845883 0.0082382 ]
[ 0.00000000e+00 3.29976046e-10 5.39367189e-07 8.10528027e-05
4.71001953e-03 3.70178834e-01 9.52707020e-01 9.99372657e-01
9.99999981e-01 9.99999998e-01]
"""
if feature not in ALL_FEATURES:
raise ValueError(
'Input value must in {"AS", "F", "M_AS", "M_IS", "W", "Distance"}')
if methods not in METHOD:
raise ValueError(
'Input value must in {"LombScargleFast","LombScargle"}')
# get data
if mouse is None:
data_all = aggregate_data(feature=feature, bin_width=bin_width)
n_mouse_in_strain = len(
set(data_all.loc[data_all['strain'] == strain]['mouse']))
data = [[] for i in range(n_mouse_in_strain)]
t = [[] for i in range(n_mouse_in_strain)]
for i in range(n_mouse_in_strain):
data[i] = data_all.loc[(data_all['strain'] == strain) & (
data_all['mouse'] == i)][feature]
t[i] = np.array(np.arange(0, len(data[i]) *
bin_width / 60, bin_width / 60))
data = [val for sublist in data for val in sublist]
N = len(data)
t = [val for sublist in t for val in sublist]
else:
if feature == 'Distance':
data = aggregate_movement(
strain=strain, mouse=mouse, bin_width=bin_width)
N = len(data)
t = np.arange(0, N * bin_width / 60, bin_width / 60)
else:
data = aggregate_interval(
strain=strain, mouse=mouse,
feature=feature, bin_width=bin_width)
N = len(data)
t = np.arange(0, N * bin_width / 60, bin_width / 60)
y = data
# fit model
if disturb_t is True:
t = t + np.random.uniform(-bin_width / 600, bin_width / 600, N)
if methods == 'LombScargleFast':
model = LombScargleFast(fit_period=False).fit(t=t, y=y)
elif methods == 'LombScargle':
model = LombScargle(fit_period=False).fit(t=t, y=y)
# calculate periods' LS power
if search_range_fit is None:
periods, power = model.periodogram_auto(nyquist_factor=nyquist_factor)
else:
periods = search_range_fit
power = model.periodogram(periods=search_range_fit)
# find best cycle
model.optimizer.period_range = search_range_find
cycle, cycle_power = model.find_best_periods(
return_scores=True, n_periods=n_cycle)
cycle_pvalue = 1 - (1 - np.exp(cycle_power / (-2) * (N - 1))) ** (2 * N)
# visualization
if plot is True:
lombscargle_visualize(periods=periods, power=power, sig=sig, N=N,
cycle_power=cycle_power,
cycle_pvalue=cycle_pvalue, cycle=cycle)
if gen_doc is True:
return periods, power, sig, N, cycle, cycle_power, cycle_pvalue
return cycle, cycle_power, cycle_pvalue
