Learn R Programming

dCovTS (version 1.0)

ADCF: Auto-Distance Correlation Function

Description

Computes the auto-distance correlation function of a univariate time series.

Usage

ADCF(x, MaxLag)

Arguments

x
numeric vector or univariate time series.
MaxLag
maximum lag order at which to calculate the ADCF. Default is 15.

Value

  • Returns a vector, whose length is determined by MaxLag, and contains the estimated ADCF.

Details

Distance covariance and correlation firstly introduced by Szekely et al. (2007) are new measures of dependence between two random vectors. Zhou (2012) extended this measure to time series framework. For a univariate time series, ADCF computes the auto-distance correlation function, $R_X(j)$, between ${X_t}$ and ${X_{t-|j|}}$, whereas ADCV computes the auto-distance covariance function between them, denoted by $V_X(j)$. Formal definition of $R_X(\cdot)$ and $V_X(\cdot)$ can be found in Zhou (2012) and Fokianos and Pitsillou (2016). The empirical auto-distance correlation function, $\hat{R}_X(j)$, is computed as the square root of $$\hat{R}_X^2(j)=\frac{\hat{V}_X^2(j)}{\hat{V}_X^2(0)}, ~~~~~j=0, \pm 1, \pm 2, \dots$$ for $\hat{V}_X^2(0) \neq 0$ and zero otherwise, where $\hat{V}_X(\cdot)$ is a function of the double centered Euclidean distance matrices of the sample $X_t$ and its lagged sample $X_{t-|j|}$ (see ADCV for more details). Theoretical properties of this measure can be found in Fokianos and Pitsillou (2016). mADCF computes the auto-distance correlation function of a multivariate time series.

References

Fokianos K. and M. Pitsillou (2016). Consistent testing for pairwise dependence in time series. Technometrics, http://dx.doi.org/10.1080/00401706.2016.1156024. Szekely, G. J., M. L. Rizzo and N. K. Bakirov (2007). Measuring and testing dependence by correlation of distances. The Annals of Statistics $\textbf{35}$, 2769-2794, http://dx.doi.org/10.1214/009053607000000505. Zhou, Z. (2012). Measuring nonlinear dependence in time series, a distance correlation approach. Journal of Time Series Analysis $\textbf{33}$, 438-457, http://dx.doi.org/10.1111/j.1467-9892.2011.00780.x.

See Also

ADCFplot, ADCV, mADCF

Examples

Run this code
x <- rnorm(1000)
ADCF(x)

ADCF(ldeaths,18)

Run the code above in your browser using DataLab