eventInterval-package {eventInterval}

Sequential event interval analysis

Description

Functions for analysis of rate changes in sequential events. Appropriate data are the times of observation of well defined events, such as equipment failures or deaths.

Details

Package:	eventInterval
Version:	1.0
Date:	2013-05-28
Depends:	MASS
License:	GPL (>=2)
Packaged:	2013-05-28 11:12:16 UTC; root
Built:	R 3.0.0; ; 2013-05-28 11:12:19 UTC; unix

Index:

EIglm		Perform a GLM with intervals as response variable
EIdensity	Plot the empirical and theoretical densities of intervals
EIplot		Plot the intervals against the occurrence of the events
rescale		scale numeric values into a new range

The basic model is of events that are independent and uniformly distributed in time. This assumption underlies the use of the exponential distribution in the generalized linear models produced by ‘⁠EIglm⁠’. In general, it is expected that deviations from uniformly distributed intervals follow a function that is expressed in one or more of the predictors. A predictor that is included by default is the times of the occurrence of the events. This will reveal linear changes in the rate. Other predictors may test for non-linear or cyclic changes in rate.

Event interval analysis can be a useful alternative to Poisson based analysis when few events occur in the counting intervals. Its advantage in power to detect changes in rate diminishes as the number of events increases.

This type of analysis was known as event history analysis, but the phrase is now usually applied to the analysis of the antecedents of events, whether sequential or not.

Author(s)

Jim Lemon <[e-mail]>, Maintainer: Jim Lemon <[e-mail]>

References

Maguire, B.A., Pearson, E.S. & Wynn, A.H.A. (1952) The time intervals between industrial accidents. Biometrika, 39(1/2): 168-180.

Whitworth, W.A. (1901) Choice and chance. (3rd ed.) Cambridge: Deighton Bell.

Lemon, J. (2014) The analysis of event rates using intervals. The Quantitative Methods for Psychology, 10 (1), 68-76.