Shift a time variable to have a new center (zero point)

Given a vector, shift the values to have a new center, but keeping the same minimum and maximum. Designed to work with time values where the minimum indicates the same time as the maximum (e.g., 24:00:00 is the same as 00:00:00).

Usage

timeshift(x, center = 0, min = 0, max = 1, inverse = FALSE)

Arguments

x

the time scores to shift

center

A value (between the minimum and maximum) to center the time scores. Defaults to 0, which has no effect.

min

The theoretical minimum of the time scores. Defaults to 0.

max

the theoretical maximum of the time scores. Defaults to 1.

inverse

A logical value, whether to ‘unshift’ the time scores. Defaults to FALSE.

Value

A vector of shifted time scores, recentered as specified.

Examples

## example showing centering at 11am (i.e., 11am becomes new 0)
plot((1:24)/24, timeshift((1:24)/24, 11/24))


## example showing the inverse, note that 24/24 becomes 0
plot((1:24)/24, timeshift(timeshift((1:24)/24, 11/24), 11/24, inverse = TRUE))