library(datefixR)This vignette describes the functionality of datefixR in
more detail than the README file.
DatefixR is a lightweight package consisting of two main
user-accessible functions, fix_date_char() and
fix_date_df(), which converts dates written in different
formats into R’s built-in Date
class. The former is designed to modify character vectors whilst the
latter is intended for modifying columns of a data frame (or tibble).
fix_date_app() is a third function which allows dates to be
standardized via a Shiny app interface. You can learn more about the
Shiny app in its dedicated vignette.
Practically, this package is most useful when handling date data which has been supplied via text boxes (instead of a date-specific input with a consistent date format). However, this package may also be useful to validate the format of date data (see date and month imputation).
Firstly, we will demonstrate date standardization without imputation. We consider a data frame with two columns of dates in differing formats with no missing data.
bad.dates <- data.frame(
id = seq(5),
some.dates = c(
"02/05/92",
"01-04-2020",
"1996/05/01",
"2020-05-01",
"02-04-96"
),
some.more.dates = c(
"01 03 2015",
"2nd January 2010",
"01/05/1990",
"03-Dec-2012",
"02 April 2020"
)
)
knitr::kable(bad.dates)| id | some.dates | some.more.dates |
|---|---|---|
| 1 | 02/05/92 | 01 03 2015 |
| 2 | 01-04-2020 | 2nd January 2010 |
| 3 | 1996/05/01 | 01/05/1990 |
| 4 | 2020-05-01 | 03-Dec-2012 |
| 5 | 02-04-96 | 02 April 2020 |
fix_date_df() requires two arguments, df, a
data frame (or tibble) object and col.names, a character
vector containing the names of columns to be standardized. By default,
the first column of the data frame is assumed to contain row IDs. These
IDs are used if a warning or error is raised to assist the user with
locating the source of the error. The ID column can also be manually
provided via the id argument.
The output from this function is a data frame or tibble (dependent on
the object type of the the first argument, df) with the
selected date columns now standardized and belonging to the
Date class.
fixed.dates <- fix_date_df(
bad.dates,
c("some.dates", "some.more.dates")
)
knitr::kable(fixed.dates)| id | some.dates | some.more.dates |
|---|---|---|
| 1 | 1992-05-02 | 2015-03-01 |
| 2 | 2020-04-01 | 2010-01-02 |
| 3 | 1996-05-01 | 1990-05-01 |
| 4 | 2020-05-01 | 2012-12-03 |
| 5 | 1996-04-02 | 2020-04-02 |
datefixR can handle many different formats including -,
/, ., or white space separation, year-first or day-first, and month
supplied as a number, an abbreviation or full length name.
fix_date_char() is similar to fix_date_df()
but only applies to a single character object.
fix_date_char("01 02 2014")
#> [1] "2014-02-01"datefixR currently supports dates being provided in
English, Français (French), Deutsch (German), español (Spanish), and
português (Portuguese) by recognizing both names of months in these
languages and formatting customs. Expected languages do not need to be
specified and can be provided just like any other date to be
standardized.
fix_date_char("7 de septiembre del 2014")
#> [1] "2014-09-07"Functions in datefixR assume day-first instead of
month-first when day, month, and year are all given numerically (unless
year is given first). However, this behavior can be modified by passing
format = "mdy" to function calls.
fix_date_char("01 02 2014", format = "mdy")
#> [1] "2014-01-02"If the month is given by name, then datefixR will
automatically detect the correct format without the format
argument needing to be specified by the user.
fix_date_char("July 4th, 1776")
#> [1] "1776-07-04"By default, datefixR imputes missing months as July, and
missing days of the month as the first day. As such, “1992” converts
to
fix_date_char("1992")
#> [1] "1992-07-01"The argument for defaulting to July is 1st-2nd July is halfway
through the year (on a non leap year). Therefore, assuming the year
supplied is indeed correct, the imputation has a maximum potential error
of 6 months from the true date. However, this behavior can be changed by
supplying the day.impute and month.impute
arguments with an integer corresponding to the desired day and month.
For example, day.impute = 1 and
month.impute = 1 results in the first day of January being
imputed instead which is often a more common imputation for missing date
data.
fix_date_char("1992", day.impute = 1, month.impute = 1)
#> [1] "1992-01-01"The imputation mechanism can also be modified to impute
NA if a month or day is missing by setting
day.impute or month.impute to NA.
This will also result in a warning being raised.
fix_date_char("1992", month.impute = NA)
#> Warning: NA imputed (date: 1992)
#> [1] NAFinally, imputation can be prevented by setting
day.impute or month.impute to
NULL. This will result in an error being raised if the day
or month are missing respectively.
fix_date_char("1992", month.impute = NULL)
# ERRORday.impute and month.impute can also be
passed to fix_date_df() for similar functionality.
example.df <- data.frame(
id = seq(1, 3),
some.dates = c("2014", "April 1990", "Mar 19")
)
fix_date_df(example.df, "some.dates", day.impute = 1, month.impute = 1)
#> id some.dates
#> 1 1 2014-01-01
#> 2 2 1990-04-01
#> 3 3 2019-03-01If you use this package in your research, please consider citing
datefixR. An up-to-date citation can be obtained by
running
citation("datefixR")
#>
#> To cite datefixR in publications use:
#>
#> Constantine-Cooke, Nathan . datefixR: Fix Really Messy Dates in R. R
#> package version 1.3.0. DOI: 10.5281/zenodo.5655311.
#> https://CRAN.R-project.org/package=datefixR
#>
#> A BibTeX entry for LaTeX users is
#>
#> @Manual{,
#> title = {{datefixR}: Standardize Dates in Different Formats or with Missing Data},
#> author = {Nathan Constantine-Cooke},
#> url = {https://CRAN.R-project.org/package=datefixR},
#> doi = {10.5281/zenodo.5655311},
#> note = {R package version 1.3.0},
#> }