GGIR (version 3.2-0)

g.IVIS: Calculates IV and IS

Description

To extract interdaily stability and interdaily variability as originally proposed by van Someren.

Usage

g.IVIS(Xi, epochSize = 60, threshold = NULL)

Value

InterdailyStability

IntradailyVariability

Arguments

Xi

Vector with acceleration values, e.g. ENMO metric.

epochSize

Epoch size of the values in Xi expressed in seconds.

threshold

Acceleration threshold to distinguish inactive from active

Author

Ian Meneghel Danilevicz <[e-mail]> Vincent T van Hees <[e-mail]>

References

• Eus J. W. Van Someren, Dick F. Swaab, Christopher C. Colenda, Wayne Cohen, W. Vaughn McCall & Peter B. Rosenquist. Bright Light Therapy: Improved Sensitivity to Its Effects on Rest-Activity Rhythms in Alzheimer Patients by Application of Nonparametric Methods Chronobiology International. 1999. Volume 16, issue 4.

Examples

  Xi = abs(rnorm(n = 10000,mean = 0.2))
  IVISvariables = g.IVIS(Xi=Xi)