Calculates the relative change in the standard deviation between two consecutive rolling windows.

This is an R package implementing the epidemic volatility index (EVI), as
discussed by Kostoulas et. al. (2021) and variations by Pateras et. al. (2023). EVI is a new, conceptually simple, early warning tool for oncoming epidemic waves.
EVI is based on the volatility of newly reported cases per unit of time,
ideally per day, and issues an early warning when the volatility change rate exceeds a threshold.

Konstantinos Pateras  with contributions from Larisa Kosidou

Epidemic Volatility Index as an Early-Warning Tool

Eletherios Meletis

Konstantinos Pateras

Paolo Eusebi

Matt Denwood

Polychronis Kostoulas

evi function

<dl><dt>rollsd</dt>
<dd>numeric vector - returned and stored as roll from the rollsd() function.</dd></dl>

Arguments

Calculation of the Epidemic Volatility Index — evi

<dl>

<dt>rollsd</dt>
<dd>numeric vector - returned and stored as roll from the rollsd() function.</dd>

</dl>

evi: Calculation of the Epidemic Volatility Index

Description

Usage

Arguments

Examples