DMH
An improved Directional Movement indicator using Hann windowing for smoother signals and reduced lag.
Usage
Use as a momentum oscillator with high-pass filtering to isolate cyclical momentum while removing the trend bias that corrupts standard momentum indicators.
Background
Ehlers constructs the DMH by applying a high-pass filter to the momentum calculation, removing the low-frequency trend component that causes conventional momentum to drift. The result is a zero-centered momentum oscillator that oscillates cleanly around the cycle midpoint.
Parameters
length(default: 14): Smoothing period
Formula
[ \text{PlusDM} = \text{High} - \text{High}{t-1} \text{ if } > (\text{Low} 0 ] [ \text{MinusDM} = \text{Low}} - \text{Low}) \text{ and } > 0, \text{ else {t-1} - \text{Low} \text{ if } > (\text{High} - \text{High} 0 ] [ \text{EMA} = \frac{1}{L}(\text{PlusDM} - \text{MinusDM}) + (1 - \frac{1}{L})\text{EMA}}) \text{ and } > 0, \text{ else {t-1} ] [ \text{DMH} = \frac{\sum}^{L} w_i \text{EMA{t-i+1}}{\sum\right) ]}^{L} w_i}, \text{ where } w_i = 1 - \cos\left(\frac{2\pi i}{L+1