rank_trend

Make comparisons between two versions of the same outcome by some grouping variables where trend changes are ranked first by the number of slopes that changed sign and then by the greatest mean absolute percentage change to the smallest.

rank_trend(
  new_data,
  old_data,
  numb_bins = 1L,
  comparison_var,
  id_vars,
  group_vars,
  trend_var,
  displace_old_zero = 1e-10
)

Arguments

new_data	data.table() New version of data for comparison.
old_data	data.table() Old version of data for comparison.
numb_bins	numeric() numb_bins represents the number of bins to use in the trend analysis within each grouping by group_vars. The default numb_bins is 1, which would examine the change in the slope (i.e. change in comparison_var over change in trend_var) by group_vars in the trend analysis.
comparison_var	numeric() Outcome variable to make comparisons over.
id_vars	Vector of variable names that uniquely identify both new_data and old_data.
group_vars	Level to summarize change variables for ranking. group_vars are a subset of id_vars.
trend_var	numeric() Predictor variable used to examine trend changes. trend_var is a subset of id_vars of length 1.
displace_old_zero	numeric() Displace zeros in old_data trend to prevent NaNs in change calculations. Default is 1e-10.

Value

data.table() of ranked merged data.tables, which may be a subset of the input data.tables. Rank number 1 corresponds to the greatest change in comparison_var by group_vars between new_data and old_data, rank number 2 corresponds to the second greatest change in comparison_var by group_vars, etc. NOTE: Ranks may be duplicated by group if they have the same values used for ranking.

Examples

rank_trend(new_data,
           old_data_alt,
           numb_bins = 1L,
           comparison_var = "outcome",
           id_vars = c("year", "group"),
           group_vars = "group",
           trend_var = "year")
#>    group year new_outcome old_outcome bin old_slope new_slope sign_change
#> 1:     b    1          12           4   1         4        -4           1
#> 2:     b    2           8           8   1         4        -4           1
#> 3:     b    3           4          12   1         4        -4           1
#> 4:     c    1           0           1   1         1         0           0
#> 5:     c    2           0           2   1         1         0           0
#> 6:     c    3           0           3   1         1         0           0
#> 7:     a    1           2           2   1         2         2           0
#> 8:     a    2           4           4   1         2         2           0
#> 9:     a    3           6           6   1         2         2           0
#>    pert_diff mean_abs_pert_diff numb_sign_change rank
#> 1:      -200                200                1    1
#> 2:      -200                200                1    1
#> 3:      -200                200                1    1
#> 4:      -100                100                0    2
#> 5:      -100                100                0    2
#> 6:      -100                100                0    2
#> 7:         0                  0                0    3
#> 8:         0                  0                0    3
#> 9:         0                  0                0    3