stratified_boxcox {basecamb}

Box-Cox transformation for stratified data

Description

Create Box-Cox transformation using different optimal lambda values for each stratum

Usage

stratified_boxcox(
  data,
  value_col,
  strat_cols,
  plot = FALSE,
  return = "values",
  buffer = 0,
  inverse = FALSE,
  lambdas = NULL
)

Arguments

data

data.frame containing the data

value_col

character, name of column with values to be transformed

strat_cols

character (vector), name(s) of columns to stratify by

plot

logical, should the lambda distribution be plotted?

return

character, either "values" or "lambdas"

buffer

numeric, buffer value to be added before transformation, used to ensure all positive values

inverse

logical, if TRUE, the function reverses the transformation given a list of lambdas

lambdas

if inverse == TRUE: Nested list of lambdas used in original transformation. Can be obtained by using return = "lambdas" on untransformed data

Value

if "values", vector of transformed values, if "lambdas" nested named list of used lambdas. The buffer will be equal for all strata

Author(s)

J. Peter Marquardt

Examples

data <- data.frame("value" = c(1:50, rnorm(50, 100, 10)),
                   "strat_var" = rep(c(1,2), each = 50),
                   "strat_var2" = rep(c(1, 2), 50))
lambdas <- stratified_boxcox(data = data, value_col = "value",
                             strat_cols = c("strat_var", "strat_var2"),
                             return = "lambdas")
data$value_boxed <- stratified_boxcox(data = data, value_col = "value",
                                      strat_cols = c("strat_var", "strat_var2"),
                                      return = "values")
data$value_unboxed <- stratified_boxcox(data = data, value_col = "value_boxed",
                                        strat_cols = c("strat_var", "strat_var2"),
                                        inverse = TRUE, lambdas = lambdas)