clean: Clean column data to a class

In cleaner: Fast and Easy Data Cleaning

Clean column data to a class

Description

Use any of these functions to quickly clean columns in your data set. Use clean() to pick the functions that return the least relative number of NAs. They always return the class from the function name (e.g. clean_Date() always returns class Date).

Usage

clean(x)

## S3 method for class 'data.frame'
clean(x)

clean_logical(
  x,
  true = regex_true(),
  false = regex_false(),
  na = NULL,
  fixed = FALSE,
  ignore.case = TRUE
)

clean_factor(
  x,
  levels = unique(x),
  ordered = FALSE,
  droplevels = FALSE,
  fixed = FALSE,
  ignore.case = TRUE
)

clean_numeric(x, remove = "[^0-9.,-]", fixed = FALSE)

clean_double(x, remove = "[^0-9.,-]", fixed = FALSE)

clean_integer(x, remove = "[^0-9.,-]", fixed = FALSE)

clean_character(
  x,
  remove = "[^a-z \t\r\n]",
  fixed = FALSE,
  ignore.case = TRUE,
  trim = TRUE
)

clean_currency(x, currency_symbol = NULL, remove = "[^0-9.,-]", fixed = FALSE)

clean_percentage(x, remove = "[^0-9.,-]", fixed = FALSE)

clean_Date(x, format = NULL, guess_each = FALSE, max_date = Sys.Date(), ...)

clean_POSIXct(
  x,
  tz = "",
  remove = "[^.0-9 :/-]",
  fixed = FALSE,
  max_date = Sys.Date(),
  ...
)

Arguments

x	data to clean
true	regex to interpret values as TRUE (which defaults to regex_true), see Details
false	regex to interpret values as FALSE (which defaults to regex_false), see Details
na	regex to force interpret values as NA, i.e. not as TRUE or FALSE
fixed	logical to indicate whether regular expressions should be turned off
ignore.case	logical to indicate whether matching should be case-insensitive
levels	new factor levels, may be named with regular expressions to match existing values, see Details
ordered	logical to indicate whether the factor levels should be ordered
droplevels	logical to indicate whether non-existing factor levels should be dropped
remove	regex to define the character(s) that should be removed, see Details
trim	logical to indicate whether the result should be trimmed with trimws(..., which = "both")
currency_symbol	the currency symbol to use, which will be guessed based on the input and otherwise defaults to the current system locale setting (see Sys.localeconv)
format	character string giving a date-time format as used by strptime. For clean_Date(..., guess_each = TRUE), this can be a vector of values to be used for guessing, see Examples.
guess_each	logical to indicate whether all items of x should be guessed one by one, see Examples
max_date	date (coercible with [as.Date()]) to indicate to maximum allowed of x, which defaults to today. This is to prevent that clean_Date("23-03-47") will return 23 March 2047 and instead returns 23 March 1947 with a warning.
...	for clean_Date and clean_POSIXct: other parameters passed on these functions
tz	time zone specification to be used for the conversion, if one is required. System-specific (see time zones), but "" is the current time zone, and "GMT" is UTC (Universal Time, Coordinated). Invalid values are most commonly treated as UTC, on some platforms with a warning.

Details

Using clean() on a vector will guess a cleaning function based on the potential number of NAs it returns. Using clean() on a data.frame to apply this guessed cleaning over all columns.

Info about the different functions:

• clean_logical():
  Use parameters true and false to match values using case-insensitive regular expressions (regex). Unmatched values are considered NA. At default, values are matched with regex_true and regex_false. This allows support for values "Yes" and "No" in the following languages: Arabic, Bengali, Chinese (Mandarin), Dutch, English, French, German, Hindi, Indonesian, Japanese, Malay, Portuguese, Russian, Spanish, Telugu, Turkish and Urdu. Use parameter na to override values as NA that would else be matched with true or false. See Examples.

• clean_factor():
  Use parameter levels to set new factor levels. They can be case-insensitive regular expressions to match existing values of x. For matching, new values for levels are internally temporary sorted descending on text length. See Examples.

• clean_numeric(), clean_double(), clean_integer() and clean_character():
  Use parameter remove to match values that must be removed from the input, using regular expressions (regex). In case of clean_numeric(), comma's will be read as dots and only the last dot will be kept. Function clean_character() will keep middle spaces at default. See Examples.

• clean_percentage():
  This new class works like clean_numeric(), but transforms it with as.percentage, which will retain the original values, but will print them as percentages. See Examples.

• clean_currency():
  This new class works like clean_numeric(), but transforms it with as.currency. The currency symbol is guessed based on the most traded currencies by value (see Source): the United States dollar, Euro, Japanese yen, Pound sterling, Swiss franc, Renminbi, Swedish krona, Mexican peso, South Korean won, Turkish lira, Russian ruble, Indian rupee and the South African rand. See Examples.

• clean_Date():
  Use parameter format to define a date format, or leave it empty to have the format guessed. Use "Excel" to read values as Microsoft Excel dates. The format parameter will be evaluated with format_datetime, which means that a format like "d-mmm-yy" with be translated internally to "%e-%b-%y" for convenience. See Examples.

• clean_POSIXct():
  Use parameter remove to match values that must be removed from the input, using regular expressions (regex). The resulting string will be coerced to a date/time element with class POSIXct, using as.POSIXct(). See Examples.

The use of invalid regular expressions in any of the above functions will not return an error (like in base R), but will instead interpret the expression as a fixed value and will throw a warning.

Value

The clean_* functions always return the class from the function name:

• clean_logical(): class logical

• clean_factor(): class factor

• clean_numeric() and clean_double(): class numeric

• clean_integer(): class integer

• clean_character(): class character

• clean_percentage(): class percentage

• clean_currency(): class currency

• clean_Date(): class Date

• clean_POSIXct(): classes POSIXct/POSIXt

Source

Triennial Central Bank Survey Foreign exchange turnover in April 2016 (PDF). Bank for International Settlements. 11 December 2016. p. 10.

Examples

clean_logical(c("Yes", "No"))   # English
clean_logical(c("Oui", "Non"))  # French
clean_logical(c("ya", "tidak")) # Indonesian
clean_logical(x = c("Positive", "Negative", "Unknown", "Some value"),
              true = "pos", false = "neg")

gender_age <- c("male 0-50", "male 50+", "female 0-50", "female 50+")
clean_factor(gender_age, c("M", "F"))
clean_factor(gender_age, c("Male", "Female"))
clean_factor(gender_age, c("0-50", "50+"), ordered = TRUE)

clean_Date("13jul18", "ddmmmyy")
clean_Date("12 August 2010")
clean_Date("12 06 2012")
clean_Date("October 1st 2012")
clean_Date("43658")
clean_Date("14526", "Excel")
clean_Date(c("1 Oct 13", "October 1st 2012")) # could not be fitted in 1 format
clean_Date(c("1 Oct 13", "October 1st 2012"), guess_each = TRUE)
clean_Date(c("12-14-13", "1 Oct 2012"), 
           guess_each = TRUE,
           format = c("d mmm yyyy", "mm-yy-dd")) # only these formats will be tried

clean_POSIXct("Created log on 2020/02/11 11:23 by user Joe")
clean_POSIXct("Created log on 2020.02.11 11:23 by user Joe", tz = "UTC")

clean_numeric("qwerty123456")
clean_numeric("Positive (0.143)")
clean_numeric("0,143")
clean_numeric("minus 12 degrees")

clean_percentage("PCT: 0.143")
clean_percentage(c("Total of -12.3%", "Total of +4.5%"))

clean_character("qwerty123456")
clean_character("Positive (0.143)")

clean_currency(c("Received 25", "Received 31.40"))
clean_currency(c("Jack sent £ 25", "Bill sent £ 31.40"))

df <- data.frame(A = c("2 Apr 2016", "5 Feb 2020"), 
                 B = c("yes", "no"),
                 C = c("Total of -12.3%", "Total of +4.5%"),
                 D = c("Marker: 0.4513 mmol/l", "Marker: 0.2732 mmol/l"))
df
clean(df)

cleaner documentation built on Oct. 29, 2022, 9:05 a.m.