Reformat Values

Usage

reformat(obj, ...)

# S3 method for default
reformat(obj, format, ...)

# S3 method for character
reformat(obj, format, ...)

# S3 method for factor
reformat(obj, format, ...)

# S3 method for list
reformat(obj, format, ...)

Arguments

obj

object 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.

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.

Examples


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

reformat(obj, format)
#> [1] A    b    x    NN   <NA>
#> attr(,"label")
#> [1] my label
#> Levels: A b x NN
reformat(obj, format, .string_as_fct = FALSE, .to_NA = NULL)
#> [1] "A"  "b"  "x"  "NN" ""  
#> attr(,"label")
#> [1] "my label"


# 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)
#> [1] first A     A     b     NN    NN   
#> attr(,"label")
#> [1] my label
#> Levels: A Not_present Not_a_level first b NN
reformat(obj, format, .na_last = FALSE, .to_NA = "b", .drop = FALSE)
#> [1] first A     A     <NA>  NN    NN   
#> attr(,"label")
#> [1] my label
#> Levels: A NN Not_present Not_a_level first


# 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)
  )
)

reformat(db, format)
#> $df1
#>   var1 var2
#> 1    a   F1
#> 2 <NA>   F2
#> 3    N <NA>
#> 
#> $df2
#>   var1 var2
#> 1    x  f11
#> 2 <NA>   NN
#> 3    y  F22
#>