timeSinceEvent {doBy}

Calculate "time since event" in a vector.

Description

Calculate "time since event" in a vector.

Usage

timeSinceEvent(yvar, tvar = seq_along(yvar))

Arguments

yvar

A numerical or logical vector specifying the events

tvar

An optional vector specifying time

Details

Events are coded as 1 in numeric vector (and non-events are coded with values different from 1). timeSinceEvent will give the time since event (with and without sign). In a logical vector, events are coded as TRUE and all non-events as FALSE.

Value

A dataframe with columns 'yvar', 'tvar', 'abs.tse' (absolute time since nearest event), 'sign.tse' (signed time since nearest event) and 'run' (indicator of the time window around each event).

Note

NA's in yvar are converted to zeros.

Author(s)

Søren Højsgaard, [e-mail]

See Also

subSeq, rle

Examples

## Events:
yvar <- c(0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0,
          0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0)

## Plot results:
tse <- timeSinceEvent(yvar)
plot(sign.tse ~ tvar, data=tse, type="b")
grid()
rug(tse$tvar[tse$yvar==1], col=4, lwd=4)
points(scale(tse$run), col=tse$run, lwd=2)
lines(abs.tse + .2 ~ tvar, data=tse, type="b", col=3)

## Find times for which time since an event is at most 1:
tse$tvar[tse$abs <= 1]

yvar <- c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
)

tvar <- c(207, 208, 208, 208, 209, 209, 209, 209, 210, 210, 211, 211, 
211, 212, 213, 213, 214, 214, 215, 216, 216, 216, 216, 217, 217, 
217, 218, 218, 219, 219, 219, 219, 220, 220, 221, 221, 221, 221, 
222, 222, 222)

timeSinceEvent(yvar, tvar)