reformat: Reformat Values

In dunlin: Preprocessing Tools for Clinical Trial Data

Reformat Values

Description

Reformat Values

Usage

reformat(obj, ...)

## Default S3 method:
reformat(obj, format, ...)

## S3 method for class 'character'
reformat(obj, format, ..., verbose = FALSE)

## S3 method for class 'factor'
reformat(obj, format, ..., verbose = FALSE)

## S3 method for class 'list'
reformat(
  obj,
  format,
  ...,
  verbose = get_arg("dunlin.reformat.verbose", "R_DUNLIN_REFORMAT_VERBOSE", FALSE)
)

Arguments

obj	(character, factor or ⁠list of data.frame⁠) to reformat.
...	for compatibility between methods and pass additional special mapping to transform rules. .string_as_fct (flag) whether the reformatted character object should be converted to factor. .to_NA (character) values that should be converted to NA. For factor, the corresponding levels are dropped. If NULL, the argument will be taken from the to_NAattribute of the rule. .drop (flag) whether to drop empty levels. If NULL, the argument will be taken from the dropattribute of the rule. .na_last (flag) whether the level replacing NA should be last.
format	(rule) or (list) of rule depending on the class of obj.
verbose	(flag) whether to print the format.

Value

(character, factor or ⁠list of data.frame⁠) with remapped values.

Note

When the rule is empty rule or when values subject to reformatting are absent from the object, no error is raised. The conversion to factor if .string_as_fct = TRUE) is still carried out. The conversion of the levels declared in .to_NA to NA values occurs after the remapping. NA values created this way are not affected by a rule declaring a remapping of NA values. For factors, level dropping is the last step, hence, levels converted to NA by the .to_NA argument, will be removed if .drop is TRUE. Arguments passed via reformat override the ones defined during rule creation.

the variables listed under the all_dataset keyword will be reformatted with the corresponding rule in every data set except where another rule is specified for the same variable under a specific data set name.

Examples

# Reformatting of character.
obj <- c("a", "b", "x", NA, "")
attr(obj, "label") <- "my label"
format <- rule("A" = "a", "NN" = NA)

reformat(obj, format)
reformat(obj, format, .string_as_fct = FALSE, .to_NA = NULL)

# Reformatting of factor.
obj <- factor(c("first", "a", "aa", "b", "x", NA), levels = c("first", "x", "b", "aa", "a", "z"))
attr(obj, "label") <- "my label"
format <- rule("A" = c("a", "aa"), "NN" = c(NA, "x"), "Not_present" = "z", "Not_a_level" = "P")

reformat(obj, format)
reformat(obj, format, .na_last = FALSE, .to_NA = "b", .drop = FALSE)

# Reformatting of list of data.frame.
df1 <- data.frame(
  var1 = c("a", "b", NA),
  var2 = factor(c("F1", "F2", NA))
)

df2 <- data.frame(
  var1 = c("x", NA, "y"),
  var2 = factor(c("F11", NA, "F22"))
)

db <- list(df1 = df1, df2 = df2)

format <- list(
  df1 = list(
    var1 = rule("X" = "x", "N" = NA, .to_NA = "b")
  ),
  df2 = list(
    var2 = rule("f11" = "F11", "NN" = NA)
  ),
  all_datasets = list(
    var1 = rule("xx" = "x", "aa" = "a")
  )
)

reformat(db, format)

dunlin documentation built on Oct. 31, 2024, 5:07 p.m.