yearqtr | R Documentation |
"yearqtr"
is a class for representing quarterly data.
yearqtr(x)
as.yearqtr(x, ...)
## S3 method for class 'character'
as.yearqtr(x, format, ...)
## S3 method for class 'yearqtr'
format(x, format = "%Y Q%q", ...)
x |
for |
format |
character string specifying format. For coercing to |
... |
arguments passed ot other methods. |
The "yearqtr"
class is used to represent quarterly data. Internally it holds
the data as year plus 0 for Quarter 1, 1/4 for Quarter 2
and so on in order that its internal representation is the same as
ts
class with frequency = 4
. If x
is not in this
format it is rounded via floor(4*x + .0001)/4
.
as.yearqtr.character
uses a default format of "%Y Q%q"
,
"%Y q%q"
or "%Y-%q"
according to whichever matches.
%q
accepts the numbers 1-4 (possibly with leading zeros). Due to
this %q
does not match to single digits only and consequently
formats such as as.yearqtr("Q12000", "Q%q%Y")
are ambiguous and
do not work (i.e., result in NA
).
There are coercion methods available for various classes including:
default coercion to "yearqtr"
(which coerces to "numeric"
first)
and coercion from "yearqtr"
to "Date"
(see below), "POSIXct"
,
"POSIXlt"
, "numeric"
, "character"
and "jul"
.
The last one is from the frame
package on CRAN.
There is an is.numeric
method which returns FALSE
.
There is also a date
method for as.yearqtr
usable with objects
created with package date
.
Sys.yearqtr()
returns the current year/month and methods for
min
, max
and range
are defined (by defining
a method for Summary
).
A yearqtr
mean
method is also defined.
Certain methods support a frac
argument. See yearmon
.
yearqtr
and as.yearqtr
return the first argument converted to
class yearqtr
.
The format
method returns a character string representation of
its argument first argument.
yearmon
, zoo
, zooreg
, ts
,
strptime
.
Sys.setenv(TZ = "GMT")
x <- as.yearqtr(2000 + seq(0, 7)/4)
x
format(x, "%Y Quarter %q")
as.yearqtr("2001 Q2")
as.yearqtr("2001 q2") # same
as.yearqtr("2001-2") # same
# returned Date is the fraction of the way through
# the period given by frac (= 0 by default)
dd <- as.Date(x)
format.yearqtr(dd)
as.Date(x, frac = 1)
as.POSIXct(x)
suppressWarnings(RNGversion("3.5.0"))
set.seed(1)
zz <- zoo(rnorm(8), x, frequency = 4)
zz
as.ts(zz)
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