epidate {epitools} | R Documentation |
Convert character vector of dates into multiple legible formats.
epidate(x, format = "%m/%d/%Y", cal.dates = FALSE, before = 7, after = 7, sunday = TRUE)
x |
character vector of dates to be converted |
format |
format of character vector of dates |
cal.dates |
Calendar dates that contains x , starting 7
days 'before' (default) until 7 days 'after' x |
before |
defines lower limit of cal.dates : default is 7
days before earliest date in x |
after |
defines upper limit of cal.dates : default is 7
days after latest date in x |
sunday |
first day of the week is either Sunday (default) or Monday |
Dates can come in many formats (e.g., November 12, 2001, 12Nov01, 11/12/2001, 11/12/01, 2001-11-12) and need to be converted into other formats for data analysis, graphical displays, generating reports, etc.
There is tremendous flexibility in converting any character vector
with sufficient information to be converted into a unique date. For
complete options for the format
option see
strptime
.
dates |
dates wtih date-time class |
julian |
number of days since 1970-01-01 |
mday |
day of the month: 1-31 |
mon |
month of the year: 0-11 |
month |
month: January, February, March, ... |
month2 |
month: Jan, Feb, Mar, ... |
firstday |
first day of the week: Sunday or Monday |
week |
week of the year: 0-53 |
year |
year: YYYY |
yr |
year: YY |
wday |
day of the week: 0-6 |
weekday |
weekday: Monday, Tuesday, Wednesday, ... |
wkday |
weekday: Mon, Tue, Wed, ... |
yday |
day of the year: 0-365 |
quarter |
quarter of the year: Q1, Q2, Q3, Q4 |
cdates |
Calendar dates that contains dates |
cjulian |
Julian calendar dates |
Visit http://www.epitools.net for the latest.
Tomas Aragon, aragon@berkeley.edu, http://www.medepi.com
none
epitools
: as.week
DateTimeClasses
to learn about date-time classes
as.Date
to convert character vector of dates into
calendar dates with date-time class (done by epidate
)
strptime
to convert date-time character strings
into a date-time class
format.POSIXlt
or
format.POSIXlt
to convert date-time classes into
character representations
as.POSIXlt
to convert either date-time objects or
date-time character strings into a human legible date-time class (done
by epidate
)
as.POSIXct
to convert either date-time objects or
date-time character strings into a continuous time date-time class
(not done by epidate
)
weekdays
, months
,
quarters
, or julian
, to convert
date-time objects into weekdays, months, quarters, or julian
representations, respectively (all are done by epidate
)
#x <- c("12/1/03", "11/2/03", NA, "1/7/04", "1/14/04", "8/18/04") #epidate(x, format = "%m/%d/%y") #epidate(x, format = "%m/%d/%y", TRUE) # ###convert vector of disease weeks into vector of mid-week dates #dwk <- sample(0:53, 100, replace = TRUE) #wk2date <- paste(dwk, "/", "Wed", sep="") #wk2date[1:10] #wk2date2 <- epidate(wk2date, format = "%U/%a") #wk2date2$dates[1:20]