Dataset.resample(freq, dim, how='mean', skipna=None, closed=None, label=None, base=0, keep_attrs=False)

Resample this object to a new temporal resolution.

Handles both downsampling and upsampling. Upsampling with filling is not yet supported; if any intervals contain no values in the original object, they will be given the value NaN.


freq : str

String in the ‘#offset’ to specify the step-size along the resampled dimension, where ‘#’ is an (optional) integer multipler (default 1) and ‘offset’ is any pandas date offset alias. Examples of valid offsets include:

  • ‘AS’: year start
  • ‘QS-DEC’: quarterly, starting on December 1
  • ‘MS’: month start
  • ‘D’: day
  • ‘H’: hour
  • ‘Min’: minute

The full list of these offset aliases is documented in pandas [R29].

dim : str

Name of the dimension to resample along (e.g., ‘time’).

how : str or func, optional

Used for downsampling. If a string, how must be a valid aggregation operation supported by xarray. Otherwise, how must be a function that can be called like how(values, axis) to reduce ndarray values along the given axis. Valid choices that can be provided as a string include all the usual Dataset/DataArray aggregations (all, any, argmax, argmin, max, mean, median, min, prod, sum, std and var), as well as first and last.

skipna : bool, optional

Whether to skip missing values when aggregating in downsampling.

closed : ‘left’ or ‘right’, optional

Side of each interval to treat as closed.

label : ‘left or ‘right’, optional

Side of each interval to use for labeling.

base : int, optionalt

For frequencies that evenly subdivide 1 day, the “origin” of the aggregated intervals. For example, for ‘24H’ frequency, base could range from 0 through 23.

keep_attrs : bool, optional

If True, the object’s attributes (attrs) will be copied from the original object to the new one. If False (default), the new object will be returned without attributes.


resampled : same type as caller

This object resampled.


[R29](1, 2) http://pandas.pydata.org/pandas-docs/stable/timeseries.html#offset-aliases