dev
Mean Absolute Deviation
dev(source, length)
Parameters
Mean Absolute Deviation - dev(source, length)
Calculates the mean absolute deviation of a series from its simple moving average.
This measures the average distance between each value and the mean, providing
a measure of dispersion similar to standard deviation but using absolute differences.
- source (field): The data series to calculate deviation on
- Valid inputs: close, open, high, low, or any indicator output
- length (int): Number of periods for the calculation
- Common values: 20 (standard), 14, 30
- Range: 1 to any positive integer
Formula
DEV = AVG(|source[i] - SMA(source, length)|) for i in [0, length-1]
Where:
- SMA(source, length) = Simple Moving Average of source
- |x| = Absolute value of x
- AVG = Average over the period window
Examples
dev(close, 20); # Standard 20-period deviation
dev(close, 14); # 14-period deviation
dev(close, 20) > 2.0; # High dispersion condition
x = dev(close, 20); x > dev(close, 50); # Short-term vs long-term volatility
Returns
Mean absolute deviation value (always non-negative, same units as source)