as.hour {epitools} | R Documentation |
Convert date-time object into hour or half-hour units
as.hour(x, mindt, maxdt, half.hour = FALSE)
x |
Date-time object in standard format: for example, "2004-12-23 08:27:00", "2004-12-23 08:27", "2004-12-23" |
mindt |
[required] Date-time object in standard format that will form the lower
boundary of the hour or half-hour time categories. mindt must
less than or equal to the minimum value in x , and must be rounded
off to the nearst hour for hour categories (e.g., HH:00:00) or rounded
off to the nearest half-hour for half-hour categories (e.g., HH:30:00).
|
maxdt |
[required] Date-time object in standard format that will form the upper
boundary of the hour or half-hour time categories. maxdt must
greater than or equal to the minimum value in x , and must be rounded
off to the nearst hour for hour categories (e.g., HH:00:00) or rounded
off to the nearest half-hour for half-hour categories (e.g., HH:30:00).
|
half.hour |
Set to TRUE for half-hour categories. |
This function (1) converts standard date-time objects into 1-hour or
1/2-hour categories, and (2) generates levels for range of values that
that the new 1-hour or 1/2-hour categories can take. These levels are
use for converting x into a factor and for providing names for labeling
the x-axis in plot. This function is used by epicurves.hours
.
$ct |
Date-time object that contains the number of seconds since the beginning
of 1970 as a numeric vector and produced by as.POSIXct . You
can use as.POSIXlt to convert this output in human legible
(already done by this function).
|
$sec |
seconds |
$min |
minutes |
$hour |
hours (0-23) |
$hour12 |
hours (1-12) |
$stratum |
number of hours or 1/2 hours since beginning of 1970 |
$stratum2 |
factor (categorical variable) with number of hours of 1/2 hours since
beginning of 1970 using $cstratum as the levels
|
$stratum3 |
factor (categorical variable) in standard date-time format indicating
number of hours or 1/2 hours since beginning of 1970 using
$cstratum2 as the levels
|
$cstratum |
levels for creating $stratum2 factor |
$cstratum2 |
levels for creating $stratum3 factor |
$csec |
seconds from $cstratum2 |
$cmin |
minutes from $cstratum2 |
$chour |
hours from $cstratum2 in 24-hour format |
$chour12 |
hours from $cstratum2 in 12-hour format |
$campm |
corresponding 'AM' or 'PM' for $chour12 |
$campm2 |
corresponding 'am' or 'pm' for $chour12 |
$cweekday |
day of the week for $cstratum2 |
$cwkday |
abbreviated day of the week for $cstratum2 |
$cmday |
day of the month for $cstratum2 |
$cmonth |
month for $cstratum2 |
$cmon |
abbreviated month for $cstratum2 |
$cyear |
year for $cstratum2 |
$half.hour |
FALSE (default) for 1-hour categories; TRUE for 1/2-hour categories |
Visit http://www.epitools.net for the latest.
Tomas Aragon, aragon@berkeley.edu, http://www.medepi.com
none
epitools: as.month
, epicurve.dates
as.Date
, strptime
,
DateTimeClasses
dates <- c("1/1/04", "1/2/04", "1/3/04", "1/4/04", "1/5/04", "1/6/04", "1/7/04", "1/8/04", "1/9/04", "1/10/04", NA, "1/12/04", "1/14/04", "3/5/04", "5/5/04", "7/6/04", "8/18/04", "12/13/05", "1/5/05", "4/6/05", "7/23/05", "10/3/05") aw <- as.week(dates, format = "%m/%d/%y") aw aw2 <- as.week(dates, format = "%m/%d/%y", sunday= FALSE) aw2 aw3 <- as.week(dates, format = "%m/%d/%y", min.date="2003-01-01") aw3