Generate a tibble of epochs.

make_epochs(
  start_year = 1987,
  end_year = 2020,
  epoch_step = 5,
  epoch_overlap = TRUE
)

Arguments

start_year: Minimum year in epochs
end_year: Maximum year in epochs
epoch_step: Numeric. How many years in an epoch?
epoch_overlap: Logical. Should epochs overlap by one year? i.e. epoch_step = 10 with epoch_overlap = TRUE gives, say, 2000-2010 and 2010-2020 whereas epoch_overlap = FALSE gives 2000-2009 and 2010-2019.

Value

Tibble with columns

start: First year of epoch
end: Last year of epoch
years: List column containing the years for the epoch
epoch: Last two digits of first year and last year in epoch. e.g. 10-19.
data: List column of full path of raster files to summarise.

Examples

now <- as.numeric(format(Sys.Date(), "%Y"))
make_epochs(now - 30, now, 10)
#> # A tibble: 3 × 5
#>   start_year end_year years      epoch epoch_now
#>        <dbl>    <dbl> <list>     <ord> <lgl>    
#> 1       1994     2004 <int [11]> 94-04 FALSE    
#> 2       2004     2014 <int [11]> 04-14 FALSE    
#> 3       2014     2024 <int [11]> 14-24 TRUE     
make_epochs(now - 30, now, 10, F)
#> # A tibble: 4 × 5
#>   start_year end_year years      epoch epoch_now
#>        <dbl>    <dbl> <list>     <ord> <lgl>    
#> 1       1994     1994 <int [1]>  94-94 FALSE    
#> 2       1995     2004 <int [10]> 95-04 FALSE    
#> 3       2005     2014 <int [10]> 05-14 FALSE    
#> 4       2015     2024 <int [10]> 15-24 TRUE