periodogram_methods {zeitgebr}

Methods For Computing Periodograms

Description

These functions provides a series of methods to assess periodicity of circadian processes.

Usage

ac_periodogram(x, period_range = c(hours(16), hours(32)),
  sampling_rate = 1/mins(1), alpha = 0.05)

chi_sq_periodogram(x, period_range = c(hours(16), hours(32)),
  sampling_rate = 1/mins(1), alpha = 0.05,
  time_resolution = hours(0.1))

cwt_periodogram(x, period_range = c(hours(16), hours(32)),
  sampling_rate = 1/mins(1), alpha = 0.05, resolution = 1/512,
  n_sim = 10)

fourier_periodogram(x, period_range = c(hours(16), hours(32)),
  sampling_rate = 1/mins(1), alpha = 0.05)

ls_periodogram(x, period_range = c(hours(16), hours(32)),
  sampling_rate = 1/mins(1), alpha = 0.05, oversampling = 8)

Arguments

x

numeric vector

period_range

vector of size 2 defining minimal and maximal range of period to study (in seconds)

sampling_rate

the – implicitly regular – sampling rate of x (in hertz)

alpha

significance level

time_resolution

the resolution of periods to scan

resolution

the period resolution of the CWT (i.e. the number of suboctaves)

n_sim

the number of shuffling simulation to compute p-value (see WaveletComp::analyze.wavelet)

oversampling

the oversampling factor (see lomb::lsp)

Value

a data.table with the columns:

• period – the period (in s)

• power – the power (or equivalent) for a given period

• p_value – the significance of the power

• signif_threshold – the significance threshold of the power (at alpha)

References

• zeitgebr tutorial – the relevant rehtomics tutorial

See Also

• lomb::lsp – the orginal function for ls_periodogram

• xsp::chiSqPeriodogram – code modified from

• stats::acf – the orginal function for ac_periodogram

• WaveletComp::analyze.wavelet – the orginal function for cwt_periodogram