xarray.cftime_range¶
-
xarray.
cftime_range
(start=None, end=None, periods=None, freq='D', tz=None, normalize=False, name=None, closed=None, calendar='standard')¶ Return a fixed frequency CFTimeIndex.
Parameters: - start : str or cftime.datetime, optional
Left bound for generating dates.
- end : str or cftime.datetime, optional
Right bound for generating dates.
- periods : integer, optional
Number of periods to generate.
- freq : str, default ‘D’, BaseCFTimeOffset, or None
Frequency strings can have multiples, e.g. ‘5H’.
- normalize : bool, default False
Normalize start/end dates to midnight before generating date range.
- name : str, default None
Name of the resulting index
- closed : {None, ‘left’, ‘right’}, optional
Make the interval closed with respect to the given frequency to the ‘left’, ‘right’, or both sides (None, the default).
- calendar : str
Calendar type for the datetimes (default ‘standard’).
Returns: - CFTimeIndex
See also
Notes
This function is an analog of
pandas.date_range
for use in generating sequences ofcftime.datetime
objects. It supports most of the features ofpandas.date_range
(e.g. specifying how the index isclosed
on either side, or whether or not tonormalize
the start and end bounds); however, there are some notable exceptions:- You cannot specify a
tz
(time zone) argument. - Start or end dates specified as partial-datetime strings must use the ISO-8601 format.
- It supports many, but not all, frequencies supported by
pandas.date_range
. For example it does not currently support any of the business-related, semi-monthly, or sub-second frequencies. - Compound sub-monthly frequencies are not supported, e.g. ‘1H1min’, as these can easily be written in terms of the finest common resolution, e.g. ‘61min’.
Valid simple frequency strings for use with
cftime
-calendars include any multiples of the following.Alias Description A, Y Year-end frequency AS, YS Year-start frequency M Month-end frequency MS Month-start frequency D Day frequency H Hour frequency T, min Minute frequency S Second frequency Any multiples of the following anchored offsets are also supported.
Alias Description A(S)-JAN Annual frequency, anchored at the end (or beginning) of January A(S)-FEB Annual frequency, anchored at the end (or beginning) of February A(S)-MAR Annual frequency, anchored at the end (or beginning) of March A(S)-APR Annual frequency, anchored at the end (or beginning) of April A(S)-MAY Annual frequency, anchored at the end (or beginning) of May A(S)-JUN Annual frequency, anchored at the end (or beginning) of June A(S)-JUL Annual frequency, anchored at the end (or beginning) of July A(S)-AUG Annual frequency, anchored at the end (or beginning) of August A(S)-SEP Annual frequency, anchored at the end (or beginning) of September A(S)-OCT Annual frequency, anchored at the end (or beginning) of October A(S)-NOV Annual frequency, anchored at the end (or beginning) of November A(S)-DEC Annual frequency, anchored at the end (or beginning) of December Finally, the following calendar aliases are supported.
Alias Date type standard, proleptic_gregorian cftime.DatetimeProlepticGregorian
gregorian cftime.DatetimeGregorian
noleap, 365_day cftime.DatetimeNoLeap
all_leap, 366_day cftime.DatetimeAllLeap
360_day cftime.Datetime360Day
julian cftime.DatetimeJulian
Examples
This function returns a
CFTimeIndex
, populated withcftime.datetime
objects associated with the specified calendar type, e.g.>>> xr.cftime_range(start='2000', periods=6, freq='2MS', calendar='noleap') CFTimeIndex([2000-01-01 00:00:00, 2000-03-01 00:00:00, 2000-05-01 00:00:00, 2000-07-01 00:00:00, 2000-09-01 00:00:00, 2000-11-01 00:00:00], dtype='object')
As in the standard pandas function, three of the
start
,end
,periods
, orfreq
arguments must be specified at a given time, with the other set toNone
. See the pandas documentation for more examples of the behavior ofdate_range
with each of the parameters.