Takes a numeric vector and will return the velocity of that vector.
Arguments
- .data
The data being passed that will be augmented by the function.
- .value
This is passed
rlang::enquo()to capture the vectors you want to augment.- .names
The default is "auto"
Details
Takes a numeric vector and will return the velocity of that vector. The velocity of a time series is computed by taking the first difference, so $$x_t - x_t1$$
This function is intended to be used on its own in order to add columns to a tibble.
See also
Other Augment Function:
ts_acceleration_augment()
Examples
suppressPackageStartupMessages(library(dplyr))
len_out = 10
by_unit = "month"
start_date = as.Date("2021-01-01")
data_tbl <- tibble(
date_col = seq.Date(from = start_date, length.out = len_out, by = by_unit),
a = rnorm(len_out),
b = runif(len_out)
)
ts_velocity_augment(data_tbl, b)
#> # A tibble: 10 × 4
#> date_col a b velocity_b
#> <date> <dbl> <dbl> <dbl>
#> 1 2021-01-01 -2.54 0.961 NA
#> 2 2021-02-01 0.797 0.392 -0.570
#> 3 2021-03-01 -0.587 0.497 0.106
#> 4 2021-04-01 -1.06 0.626 0.129
#> 5 2021-05-01 -0.0775 0.0835 -0.543
#> 6 2021-06-01 -1.25 0.339 0.255
#> 7 2021-07-01 -1.46 0.794 0.456
#> 8 2021-08-01 0.943 0.116 -0.678
#> 9 2021-09-01 1.09 0.803 0.687
#> 10 2021-10-01 -0.571 0.666 -0.138