Fields in CFTime and CFClimatology classes
have been made private, corresponding active fields added.
CFClimatology instances can now be extended with the
+ operator.
When extending a CFTime or CFClimatology
instance with another such instance using the + operator,
bounds are preserved if both instances have bounds set.
Added method CFTime$doy() to calculate the day-of-year
from offsets or supplied dates, using the calendar of the instance.
Documentation updated.
CFtime 1.7.2
Maintenance release
Time units can use SI decimal multiples or sub-multiples, such as
“µs” or “kiloyear”.
Setting bad boundary values generates a warning instead of an
error.
CFCalendar and subclasses use active fields for all
properties.
CRAN landing page links to github.io documentation.
CFtime 1.7.1
Maintenance release
Added length field to class CFTime.
Added format.CFTime() S3 method.
Added "[.CFTime" S3 method.
Documentation has been moved from vignettes to a website on
github.io.
CFtime 1.7.0
CFtime is now hosted on Github through the R-CF organization: all
things related to the CF Metadata Conventions in R.
New sequence-like method to create CFTime
instances.
New methods CFTime$copy() and
CFTime$subset() to create copies of the entire
CFTime instance or a subset thereof, including boundary
values if they are set.
Fixed error on year 0 timestamps.
CFtime 1.6.2
CFTime$indexOf() method has new
rightmost.closed argument with default value
FALSE. Invalid return values are always NA,
also for values outside of range. Boundary values are fully considered
so when boundary values are not contiguous, results may be
NA when values of x do not fall within the
bounds of a coordinate.
Fixed CFTime attribute of a “season” factor when the
last factor level is the first season in the year.
CFtime 1.6.1
Deprecated “gregorian” calendar automatically converted to the
equivalent “standard”.
CFCalendar$add_day() method added to add a day to a
data.frame of date parts, using calendar logic.
API change: Bounds are now always fully specified
so logical arguments should no longer be used, except in setting
regular, consecutive bounds (bounds <- TRUE). If bounds
have not been set, a NULL value is returned. This is to
ensure that factorizing to “approximate” time units (such as a month)
will give correct results for the bounds. (Old API deprecated by
November 2025, removed early 2026.)
CFtime 1.6.0
New class CFClimatology to manage climatological
statistics. Method CFTime$factor() with an era
argument will now have a CFClimatology instance attached to
the attribute “CFTime” of its return value.
New class CFCalendarNone for a calendar with no annual
cycle. Such a calendar represents a single instant in time, which may be
useful for experiments on a fixed moment during the year.
str() for CFTime and
CFClimatology gives compact information.
Fixed new CFTime instance for factor with a “day” or
“dekad” period where the last factor level is not at the end of the
year.
CFTime$new() with a single character string offset will
generate only the single corresponding offset.
Test coverage near-complete.
Fixed inconsistent documentation for functions.
Minor code fixes.
CFtime 1.5.1
CFTime$slice() can now work with a single or multiple
timestamp values.
Test coverage increased.
Documentation updated, all runnable example code uses
ncdfCF package.
Minor code fixes.
CFtime 1.5.0
Code is updated to align with the CF 1.12 release. Specifically,
calendars utc and tai are added.
standard calendar now uses mixed Gregorian/Julian
calendar as defined in the CF Metadata Conventions.
proleptic_gregorian is now a separate calendar with its own
code base.
Negative offsets from a calendar origin are allowed.
Code is refactored to R6. R6 class CFTime replaces S4 class CFtime
(note the difference in case). S4 class CFdatum has been replaced by
hierarchy of R6 CFCalendar classes, with various non-exported functions
converted into methods of CFCalendar. The code is now much cleaner and
easier to extend, such as with the two new calendars utc
and tai.
ISO8601 timestamps can use a comma “,” as decimal mark to separate a
fractional part from a time element, in addition to the dot “.”.
Do not drop degenerate dimension on bounds when only 1 offset is
included in subsetting.
CFtime 1.4.1
Method slab() has an additional argument
rightmost.closed to indicate if the upper extreme value
should be included in the result.
Fixed bounds information on CFtime instances returned from methods
indexOf() and slab().
Several minor code improvements.
CFtime 1.4.0
Bounds that define intervals around offsets can be associated with a
CFtime instance and retrieved as raw offset values or as formatted
timestamps.
Methods that subset a CF time series (e.g. CFfactor(),
cut(), slab()) now have an attribute “CFtime”
(among possible others) that describes the “time” dimension of the
analysis result applying the subset. In other words, if CFtime instance
‘Acf’ describes the temporal dimension of data set ‘A’ and a factor ‘Af’
is generated from ‘Acf’, then Bcf <- attr(Af, "CFtime")
describes the temporal dimension of the result of, say,
B <- apply(A, 1:2, tapply, Af, FUN).
New indexOf() method added that returns the indices of
supplied timestamps in a CFtime instance, optionally with a fractional
part. This can be used to extract specific time steps, or to interpolate
between time steps using the fractional part, from the time dimension of
the data set associated with the CFtime instance. A vector of indices
(e.g. referring to slices of the data set) can also be supplied, in
which case valid indices are returned, with the new CFtime
instance.
New cut() method added to generate a factor, similar to
cut.POSIXt() but with some differences in the
arguments.
CFfactor() now supports a period “quarter”, for
calendar quarters.
format() method added that generates a character vector
of timestamps for the offsets in a CFtime instance. The format is
specified using the flags used in strptime(), with some
limitations. In particular, locale-specific formatting is limited to
month names and no weekday information can be generated. The
range() method has a new “format” parameter to support the
same functionality and timestamps can also be generated for the extremes
of the bounds, if set.
as_character() and length() methods added
that return a vector of timestamps or the number of offsets in a CFtime
instance, respectively.
Several functions have been renamed (most notably
CFtimestamp() to as_timestamp(),
CFcomplete() to is_complete(),
CFrange() to the standard generic method
range(), and CFsubset() to
slab()) to be more consistent with the R universe. The
original functions are now flagged as being deprecated. Some datum
functions (deep down where regular mortals do not dwell) have been
deleted.
Time zone designator “UTC” accepted when parsing timestamps to
offsets.
Minor code fixes, see GitHub commits.
Documentation updated, with description of new functions.
CFtime 1.3.0
Two CFtime instances can be added if they have compatible calendars
and units. The earlier origin is preserved in the result and offsets
from the later instance are incremented by the appropriate amount. As
before, in the result offsets are in the order of the specified CFtime
instances.
A new function CFsubset() can be used to retrieve a logical vector
that indicates which time steps in a CFtime instance fall between two
timestamps. This is useful to slice data during reading from file or
analysis.
Time zone information is managed at the level of the datum. If a
vector of character timestamps is parsed and found to have different
time zones, a warning is generated.
Much reduced memory footprint.
Minor code fixes, see GitHub commits.
Codecov.io test coverage monitoring added.
Documentation updated, with description of new functions.
CFtime 1.2.0
Datum units “years” and “months” added. While these units are
discouraged by the CF Metadata Conventions due to their problematic
definition, there are quite a few data sets out there that use these
units nonetheless. For this reason, reading existing files with such
datum units is supported (converting offsets to time elements is easy)
but parsing timestamps is not (calculating offsets from time elements is
possible but tedious and slow). Should there be a definite need, open an
issue on GitHub and make a very good case why this
functionality is required.
CFresolution() returns the average separation between elements in a
time series, in units of the datum.
CFcomplete() indicates if the time series is complete, meaning that
there are no gaps in the time series. This also works for time series
with a somewhat variable length such as monthly data with a “days” datum
unit. This works for all but the most exotic time dimension
constructions.
CFtimestamp() produces a timestamp for all midnight values if the
datum unit is “hours”, “minutes” or “seconds”. The “time” format has
been removed. For “standard”, “gregorian” and “proleptic_gregorian”
calendars output can be generated as POSIXct by specifying the new
argument asPOSIX = TRUE – defaults to FALSE,
the previous behaviour so the API is not broken.
Minor documentation updates.
Assorted minor code fixes, see GitHub commits.
CFtime 1.1.0
CFtime() can now also be invoked with a vector of character
timestamps as offsets, or with a single timestamp to create a complete
time series from the datum to the indicated timestamp.
CFtimestamp() can now automatically select the best format for the
time series.
New CFfactor_units() and CFfactor_coverage() functions.
CFfactor_units() will tell you how many time units compose every level
of a factor. CFfactor_coverage() computes the actual or relative number
of time units in the factor levels from the time series in a CFtime
instance with which the factor was created. This will enable you to
assess the completeness of your time series (and perhaps filter out
factor levels below a certain coverage threshold) and it can be useful
in computing absolute values from average values, as is often useful
when computing anomalies.
Global constants are now defined in a package environment, CFt.
Documentation expanded, updated and fixed.
Assorted minor code fixes, see GitHub commits.
CFtime 1.0.0
This version supports all CF Metadata Conventions calendars for use
with climate projection data.
You can create timestamps from the offsets in the files and create
factors that greatly simplify working with climate change data.