g.IVIS: Calculates IV and IS

In GGIR: Raw Accelerometer Data Analysis

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)

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

Value

InterdailyStability
IntradailyVariability

Author(s)

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)

GGIR documentation built on April 3, 2025, 6 p.m.