rolling_std
statisticsCalculates rolling (moving) standard deviation over a window of rows
Syntax
rolling_std(column, window_size, min_periods?) Parameters
column (string) Column name to calculate rolling std on
window_size (number) Number of periods in the rolling window
min_periods (number) optional Minimum number of observations required to have a result (defaults to window_size)
Returns
dataframe or array DataFrame or Array with additional {column}_rolling_std field/column
Examples
3-period rolling standard deviation
Input:
.value | rolling_std(3) Output:
[null, null, 1.2, 1.5, 1.1, ...] 7-day window, requires at least 5 values
Input:
.price | rolling_std(7, 5) Output:
[null, null, null, null, 2.3, 2.8, 3.1, ...] Analyze volatility
Input:
{ price: .price, volatility: (.price | rolling_std(30)) } Output:
{"price": [100, 102, 98], "volatility": [null, null, 1.63]} The rolling_std() function calculates rolling (moving) standard deviation over a sliding window of rows.
Usage
Use rolling_std() for analyzing volatility, detecting changes in variance over time, and monitoring data stability in time series.