utils_split_funs: Custom split functions

Description

Collection of useful functions that are expanding on the core list of functions provided by rtables. See rtables::custom_split_funs and rtables::make_split_fun() for more information on how to make a custom split function. All these functions work with rtables::split_rows_by() argument split_fun to modify the way the split happens. For other split functions, consider consulting rtables::split_funcs.

Usage

ref_group_position(position = "first")
level_order(order)

Value

ref_group_position() returns an utility function that puts the reference group as first, last or at a certain position and needs to be assigned to split_fun.

level_order() returns an utility function that changes the original levels' order, depending on input order and split levels.

Arguments

position: (string or integer)
position to use for the reference group facet. Can be "first", "last", or a specific position.
order: (character or numeric)
vector of ordering indices for the split facets.

Functions

ref_group_position(): Split function to place reference group facet at a specific position during post-processing stage.
level_order(): Split function to change level order based on an integer vector or a character vector that represent the split variable's factor levels.

Examples

Run this code

library(dplyr)

dat <- data.frame(
  x = factor(letters[1:5], levels = letters[5:1]),
  y = 1:5
)

# With rtables layout functions
basic_table() %>%
  split_cols_by("x", ref_group = "c", split_fun = ref_group_position("last")) %>%
  analyze("y") %>%
  build_table(dat)

# With tern layout funcitons
adtte_f <- tern_ex_adtte %>%
  filter(PARAMCD == "OS") %>%
  mutate(
    AVAL = day2month(AVAL),
    is_event = CNSR == 0
  )

basic_table() %>%
  split_cols_by(var = "ARMCD", ref_group = "ARM B", split_fun = ref_group_position("first")) %>%
  add_colcounts() %>%
  surv_time(
    vars = "AVAL",
    var_labels = "Survival Time (Months)",
    is_event = "is_event",
  ) %>%
  build_table(df = adtte_f)

basic_table() %>%
  split_cols_by(var = "ARMCD", ref_group = "ARM B", split_fun = ref_group_position(2)) %>%
  add_colcounts() %>%
  surv_time(
    vars = "AVAL",
    var_labels = "Survival Time (Months)",
    is_event = "is_event",
  ) %>%
  build_table(df = adtte_f)

# level_order --------
# Even if default would bring ref_group first, the original order puts it last
basic_table() %>%
  split_cols_by("Species", split_fun = level_order(c(1, 3, 2))) %>%
  analyze("Sepal.Length") %>%
  build_table(iris)

# character vector
new_order <- level_order(levels(iris$Species)[c(1, 3, 2)])
basic_table() %>%
  split_cols_by("Species", ref_group = "virginica", split_fun = new_order) %>%
  analyze("Sepal.Length") %>%
  build_table(iris)