A Function to Sample the Annual Percentage Decrease with Uncertainty

A Function to Sample the Annual Percentage Decrease with Uncertainty

sample_per_decrease(df, max_year = NULL, min_year = NULL,
  samples = 100, years_to_avg = 3)

Arguments

df	A dataframe containing a year variable and with the second variable being the one to sample from.
max_year	Numeric, set as greater than the maximum year in the dataframe if interested in projection. Defaults to NULL. If specified, then an average of the percentage decrease for a set number of years is taken. This is specified with years_to_avg.
min_year	Numeric, set as smaller than the minimum year in the dataframe if interested in backwards projection. Defaults to NULL. If specified, then an average of the percentage decrease for a set number of years is taken. This is specified with years_to_avg.
samples	Numeric, the number of samples to take.
years_to_avg	Numeric, the number of years over which to average the percentage decrease when estimating the ongoing percentage decrease.

Value

A dataframe containing annual percentage decrease samples.

Examples

 df <- data.frame(year = c(2000:2010), measure = seq(10, 110, 10))

sample_per_decrease(df, samples = 2)
#>    year sample prop_decrease_sample
#> 1  2001      1          -0.91639928
#> 2  2001      2          -0.98043991
#> 3  2002      1          -0.49002278
#> 4  2002      2          -0.56266488
#> 5  2003      1          -0.35892570
#> 6  2003      2          -0.35503676
#> 7  2004      1          -0.29527794
#> 8  2004      2          -0.22419860
#> 9  2005      1          -0.22118227
#> 10 2005      2          -0.25581355
#> 11 2006      1          -0.10238774
#> 12 2006      2          -0.13276572
#> 13 2007      1          -0.16145445
#> 14 2007      2          -0.15543653
#> 15 2008      1          -0.15623216
#> 16 2008      2          -0.08207690
#> 17 2009      1          -0.07652777
#> 18 2009      2          -0.14024365
#> 19 2010      1          -0.12074288
#> 20 2010      2          -0.14937032