Cesium Features - By Category

Cadence/Error

Description

all_times_nhist_numpeaks

Number of peaks (local maxima) in histogram of all possible delta_t’s.

all_times_nhist_peak1_bin

Return the (bin) index of the ith largest peak. Peaks is a list of tuples (i, x[i]) of peak indices i and values x[i], sorted in decreasing order by peak value.

all_times_nhist_peak2_bin

Return the (bin) index of the ith largest peak. Peaks is a list of tuples (i, x[i]) of peak indices i and values x[i], sorted in decreasing order by peak value.

all_times_nhist_peak3_bin

Return the (bin) index of the ith largest peak. Peaks is a list of tuples (i, x[i]) of peak indices i and values x[i], sorted in decreasing order by peak value.

all_times_nhist_peak4_bin

Return the (bin) index of the ith largest peak. Peaks is a list of tuples (i, x[i]) of peak indices i and values x[i], sorted in decreasing order by peak value.

all_times_nhist_peak_1_to_2

Compute the ratio of the values of the ith and jth largest peaks. Peaks is a list of tuples (i, x[i]) of peak indices i and values x[i], sorted in decreasing order by peak value.

all_times_nhist_peak_1_to_3

Compute the ratio of the values of the ith and jth largest peaks. Peaks is a list of tuples (i, x[i]) of peak indices i and values x[i], sorted in decreasing order by peak value.

all_times_nhist_peak_1_to_4

Compute the ratio of the values of the ith and jth largest peaks. Peaks is a list of tuples (i, x[i]) of peak indices i and values x[i], sorted in decreasing order by peak value.

all_times_nhist_peak_2_to_3

Compute the ratio of the values of the ith and jth largest peaks. Peaks is a list of tuples (i, x[i]) of peak indices i and values x[i], sorted in decreasing order by peak value.

all_times_nhist_peak_2_to_4

Compute the ratio of the values of the ith and jth largest peaks. Peaks is a list of tuples (i, x[i]) of peak indices i and values x[i], sorted in decreasing order by peak value.

all_times_nhist_peak_3_to_4

Compute the ratio of the values of the ith and jth largest peaks. Peaks is a list of tuples (i, x[i]) of peak indices i and values x[i], sorted in decreasing order by peak value.

all_times_nhist_peak_val

Peak value in histogram of all possible delta_t’s.

avg_double_to_single_step

Mean value of ratios (t[i+2] - t[i]) / (t[i+2] - t[i+1]).

avg_err

Mean of the error estimates.

avgt

Mean of the time values.

cad_probs_1

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_10

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_20

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_30

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_40

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_50

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_100

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_500

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_1000

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_5000

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_10000

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_50000

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_100000

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_500000

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_1000000

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_5000000

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cad_probs_10000000

Given the observed distribution of time lags cads, compute the probability that the next observation occurs within time minutes of an arbitrary epoch.

cads_avg

Mean value of cads (discrete difference between times).

cads_kurtosis

Kurtosis of cads (discrete difference between times).

cads_med

Median value of cads (discrete difference between times).

cads_skew

Skew of cads (discrete difference between times).

cads_std

Standard deviation of cads (discrete difference between times).

mean

Mean of observed values.

med_double_to_single_step

Median value of ratios (t[i+2] - t[i]) / (t[i+2] - t[i+1]).

med_err

Median of error estimates.

n_epochs

Total number of observed values.

std_double_to_single_step

Standard deviation of ratios (t[i+2] - t[i]) / (t[i+2] - t[i+1]).

std_err

Standard deviation of the error estimates.

total_time

Absolute difference between max and min of time values.

General

Description

amplitude

Half the difference between the maximum and minimum magnitude.

anderson_darling

Anderson-Darling test statistic.

flux_percentile_ratio_mid20

A ratio of ((50+x) flux percentile - (50-x) flux percentile) / (95 flux percentile - 5 flux percentile), where x = percentile_range/2.

flux_percentile_ratio_mid35

A ratio of ((50+x) flux percentile - (50-x) flux percentile) / (95 flux percentile - 5 flux percentile), where x = percentile_range/2.

flux_percentile_ratio_mid50

A ratio of ((50+x) flux percentile - (50-x) flux percentile) / (95 flux percentile - 5 flux percentile), where x = percentile_range/2.

flux_percentile_ratio_mid65

A ratio of ((50+x) flux percentile - (50-x) flux percentile) / (95 flux percentile - 5 flux percentile), where x = percentile_range/2.

flux_percentile_ratio_mid80

A ratio of ((50+x) flux percentile - (50-x) flux percentile) / (95 flux percentile - 5 flux percentile), where x = percentile_range/2.

max_slope

Compute the largest rate of change in the observed data.

maximum

Maximum observed value.

median

Median of observed values.

median_absolute_deviation

Median absolute deviation (from the median) of the observed values.

minimum

Minimum observed value.

percent_amplitude

Returns the largest distance from the median value, measured as a percentage of the median.

percent_beyond_1_std

Percentage of values more than 1 std. dev. from the weighted average.

percent_close_to_median

Percentage of values within window_frac*(max(x)-min(x)) of median.

percent_difference_flux_percentile

Difference between the 95th and 5th percentiles of the data, expressed as a percentage of the median value. See Eyer (2005) arXiv:astro-ph/0511458v1, Evans & Belokurov (2005) (there the 98th and 2nd percentiles are used).

period_fast

Fits a simple sinuosidal model

qso_log_chi2_qsonu

Natural log of goodness of fit of qso-model given fixed parameters.

qso_log_chi2nuNULL_chi2nu

Natural log of expected chi2/nu for non-qso variable.

shapiro_wilk

Shapiro-Wilk test statistic.

skew

Skewness of a dataset. Approximately 0 for Gaussian data.

std

Standard deviation of observed values.

stetson_j

Robust covariance statistic between pairs of observations x,y whose uncertainties are dx,dy. If y is not given, calculates a robust variance for x.

stetson_k

A robust kurtosis statistic.

weighted_average

Arithmetic mean of observed values, weighted by measurement errors.

weighted_std_dev

Standard deviation of observed values, weighted by measurement errors.

Lomb-Scargle (Periodic)

Description

fold2P_slope_10percentile

Get alphath percentile of slopes of period-folded model.

fold2P_slope_90percentile

Get alphath percentile of slopes of period-folded model.

freq1_amplitude1

Get the amplitude of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq1_amplitude2

Get the amplitude of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq1_amplitude3

Get the amplitude of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq1_amplitude4

Get the amplitude of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq1_freq

Get the ith frequency from a fitted Lomb-Scargle model.

freq1_lambda

Get the regularization parameter of a fitted Lomb-Scargle model.

freq1_rel_phase2

Get the relative phase of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq1_rel_phase3

Get the relative phase of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq1_rel_phase4

Get the relative phase of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq1_signif

Get the significance (in sigmas) of the first frequency from a fitted Lomb-Scargle model.

freq2_amplitude1

Get the amplitude of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq2_amplitude2

Get the amplitude of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq2_amplitude3

Get the amplitude of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq2_amplitude4

Get the amplitude of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq2_freq

Get the ith frequency from a fitted Lomb-Scargle model.

freq2_rel_phase2

Get the relative phase of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq2_rel_phase3

Get the relative phase of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq2_rel_phase4

Get the relative phase of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq3_amplitude1

Get the amplitude of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq3_amplitude2

Get the amplitude of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq3_amplitude3

Get the amplitude of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq3_amplitude4

Get the amplitude of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq3_freq

Get the ith frequency from a fitted Lomb-Scargle model.

freq3_rel_phase2

Get the relative phase of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq3_rel_phase3

Get the relative phase of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq3_rel_phase4

Get the relative phase of the jth harmonic of the ith frequency from a fitted Lomb-Scargle model.

freq_amplitude_ratio_21

Get the ratio of the amplitudes of the first harmonic for the ith and first frequencies from a fitted Lomb-Scargle model.

freq_amplitude_ratio_31

Get the ratio of the amplitudes of the first harmonic for the ith and first frequencies from a fitted Lomb-Scargle model.

freq_frequency_ratio_21

Get the ratio of the ith and first frequencies from a fitted Lomb-Scargle model.

freq_frequency_ratio_31

Get the ratio of the ith and first frequencies from a fitted Lomb-Scargle model.

freq_model_max_delta_mags

Largest value minus second largest value of fitted Lomb Scargle model.

freq_model_min_delta_mags

Second smallest value minus smallest value of fitted Lomb Scargle model.

freq_model_phi1_phi2

Ratio of distances between the second minimum and first maximum, and the second minimum and second maximum, of the fitted Lomb-Scargle model.

freq_n_alias

Here we check for “1-day” aliases in ASAS / Deboss sources.

freq_signif_ratio_21

Get the ratio of the significances (in sigmas) of the ith and first frequencies from a fitted Lomb-Scargle model.

freq_signif_ratio_31

Get the ratio of the significances (in sigmas) of the ith and first frequencies from a fitted Lomb-Scargle model.

freq_varrat

Get the fraction of the variance explained by the first frequency of a fitted Lomb-Scargle model.

freq_y_offset

Get the y-intercept of a fitted Lomb-Scargle model.

linear_trend

Get the linear trend of a fitted Lomb-Scargle model.

medperc90_2p_p

Get ratio of 90th percentiles of residuals for data folded by twice the estimated period and the estimated period, respectively.

p2p_scatter_2praw

Get ratio of variability (sum of squared differences of consecutive values) of folded and unfolded models.

p2p_scatter_over_mad

Get ratio of variability of folded and unfolded models.

p2p_scatter_pfold_over_mad

Get ratio of median of period-folded data over median absolute deviation of observed values.

p2p_ssqr_diff_over_var

Get sum of squared differences of consecutive values as a fraction of the variance of the data.

scatter_res_raw

From arXiv 1101_2406v1 Dubath 20110112 paper.