# Mean¶

Running mean.

## Attributes¶

• n (float)

The current sum of weights. If each passed weight was 1, then this is equal to the number of seen observations.

## Examples¶

>>> from river import stats

>>> X = [-5, -3, -1, 1, 3, 5]
>>> mean = stats.Mean()
>>> for x in X:
...     print(mean.update(x).get())
-5.0
-4.0
-3.0
-2.0
-1.0
0.0


You can calculate a rolling average by wrapping a utils.Rolling around:

>>> from river import utils

>>> X = [1, 2, 3, 4, 5, 6]
>>> rmean = utils.Rolling(stats.Mean(), window_size=2)

>>> for x in X:
...     print(rmean.update(x).get())
1.0
1.5
2.5
3.5
4.5
5.5


## Methods¶

get

Return the current value of the statistic.

revert
update

Update and return the called instance.

Parameters

• x (numbers.Number)
• w – defaults to 1.0
update_many