Given a tibble/data.frame, you can get date from two different but comparative date ranges. Lets say you want to compare visits in one year to visits from 2 years before without also seeing the previous 1 year. You can do that with this function.
Arguments
- .data
The date.frame/tibble that holds the data
- .date_col
The column with the date value
- .start_date
The start of the period you want to analyze
- .end_date
The end of the period you want to analyze
- .periods_back
How long ago do you want to compare data too. Time units are collapsed using
lubridate::floor_date(). The value can be:second
minute
hour
day
week
month
bimonth
quarter
season
halfyear
year
Arbitrary unique English abbreviations as in the
lubridate::period()constructor are allowed.
Details
Uses the
timetk::filter_by_time()function in order to filter the date column.Uses the
timetk::subtract_time()function to subtract time from the start date.
See also
Other Time_Filtering:
ts_time_event_analysis_tbl()
Examples
suppressPackageStartupMessages(library(dplyr))
suppressPackageStartupMessages(library(timetk))
data_tbl <- ts_to_tbl(AirPassengers) %>%
select(-index)
ts_compare_data(
.data = data_tbl
, .date_col = date_col
, .start_date = "1955-01-01"
, .end_date = "1955-12-31"
, .periods_back = "2 years"
) %>%
summarise_by_time(
.date_var = date_col
, .by = "year"
, visits = sum(value)
)
#> # A tibble: 2 × 2
#> date_col visits
#> <date> <dbl>
#> 1 1953-01-01 2700
#> 2 1955-01-01 3408