CFCalendarProleptic {CFtime} | R Documentation |
Proleptic Gregorian CF calendar
Description
This class represents a standard CF calendar, but with the Gregorian calendar extended backwards to before the introduction of the Gregorian calendar. This calendar is compatible with the standard POSIXt calendar, but note that daylight savings time is not considered.
This calendar includes dates 1582-10-14 to 1582-10-05 (the gap between the Gregorian and Julian calendars, which is observed by the standard calendar), and extends to years before the year 1, including year 0.
Super class
CFtime::CFCalendar
-> CFCalendarProleptic
Methods
Public methods
Inherited methods
Method new()
Create a new CF calendar.
Usage
CFCalendarProleptic$new(nm, definition)
Arguments
nm
The name of the calendar. This must be "proleptic_gregorian". This argument is superfluous but maintained to be consistent with the initialization methods of the parent and sibling classes.
definition
The string that defines the units and the origin, as per the CF Metadata Conventions.
Returns
A new instance of this class.
Method valid_days()
Indicate which of the supplied dates are valid.
Usage
CFCalendarProleptic$valid_days(ymd)
Arguments
ymd
data.frame
with dates parsed into their parts in columnsyear
,month
andday
. Any other columns are disregarded.
Returns
Logical vector with the same length as argument ymd
has rows
with TRUE
for valid days and FALSE
for invalid days, or NA
where
the row in argument ymd
has NA
values.
Method month_days()
Determine the number of days in the month of the calendar.
Usage
CFCalendarProleptic$month_days(ymd = NULL)
Arguments
ymd
data.frame
, optional, with dates parsed into their parts.
Returns
Integer vector indicating the number of days in each month for
the dates supplied as argument ymd
. If no dates are supplied, the
number of days per month for the calendar as a vector of length 12, for
a regular year without a leap day.
Method leap_year()
Indicate which years are leap years.
Usage
CFCalendarProleptic$leap_year(yr)
Arguments
yr
Integer vector of years to test.
Returns
Logical vector with the same length as argument yr
. NA
is
returned where elements in argument yr
are NA
.
Method POSIX_compatible()
Indicate if the time series described using this calendar
can be safely converted to a standard date-time type (POSIXct
,
POSIXlt
, Date
).
Usage
CFCalendarProleptic$POSIX_compatible(offsets)
Arguments
offsets
The offsets from the CFtime instance.
Returns
TRUE
.
Method date2offset()
Calculate difference in days between a data.frame
of time
parts and the origin.
Usage
CFCalendarProleptic$date2offset(x)
Arguments
x
data.frame
. Dates to calculate the difference for.
Returns
Integer vector of a length equal to the number of rows in
argument x
indicating the number of days between x
and the origin
,
or NA
for rows in x
with NA
values.
Method offset2date()
Calculate date parts from day differences from the origin. This only deals with days as these are impacted by the calendar. Hour-minute-second timestamp parts are handled in CFCalendar.
Usage
CFCalendarProleptic$offset2date(x)
Arguments
x
Integer vector of days to add to the origin.
Returns
A data.frame
with columns 'year', 'month' and 'day' and as many
rows as the length of vector x
.
Method clone()
The objects of this class are cloneable with this method.
Usage
CFCalendarProleptic$clone(deep = FALSE)
Arguments
deep
Whether to make a deep clone.