Jitter a vector of 1D values

Modify a vector of dates by a random quantity in [-e, e]. The distribution decreases exponentially, with rate 1/2

time_jitter(x, e)

Arguments

x

Numeric or Date vector.
e

Numeric. Semi-width of the jittering interval.

Value

Vector of the same size and type as x with jittered values.

Examples

spreadrate:::time_jitter(1:10, 1)  # Numeric input
#>  [1]  1  2  4  4  5  6  7  7  9 11
spreadrate:::time_jitter(Sys.Date() + 1:10, 1)  # Date input
#>  [1] "2019-07-17" "2019-07-19" "2019-07-20" "2019-07-22" "2019-07-22"
#>  [6] "2019-07-22" "2019-07-25" "2019-07-24" "2019-07-27" "2019-07-28"

## Distribution of jittering
x <- seq.int(1e3)
xj <- spreadrate:::time_jitter(x, 5)
barplot(table(x - xj))