# Elliptic Filter Elliptic Filter is an indicator on [Vela](https://vela.luxalgo.com/chart), our next-generation charting platform, written in Pine Script®. Smooths price with a true elliptic (Cauer) low-pass design built from four targets (a 20-bar cutoff period, order 4, 0.5 dB passband ripple and 40 dB stopband attenuation), realized as cascaded biquad sections and drawn as a slope-colored line. A dashboard reports the realized passband and derived stopband edge, with alerts on turns and price crossings. - Indicator in the LuxAlgo Library, by LuxAlgo, published Jun 28, 2026. - Access: free. - Concepts: [Elliptic Filter](https://www.luxalgo.com/library/concept/elliptic-filter/) (primary) - Open on Vela: https://vela.luxalgo.com/chart?pineScriptCodeId=ivmyy826vy380rf5wqnjfkml - Page: https://www.luxalgo.com/library/indicator/elliptic-filter/ **Elliptic Filter** runs the genuine Cauer design procedure on the chart: the [elliptic filter](https://www.luxalgo.com/library/concept/elliptic-filter/) realized exactly rather than approximated. Four targets (cutoff period, order, passband ripple, stopband attenuation) fully specify the filter; the coefficients are generated once and applied as cascaded second-order sections, each normalized so the smoothed line tracks the price level exactly. The payoff is the fastest passband-to-stopband transition any classical design achieves at a given order. ## How to Trade the Elliptic Filter? - **Slope**: with Directional coloring the line flips color as it rises or falls, and the Turned Up / Turned Down alerts mark confirmed troughs and crests in the filter itself. - **Price crossings**: the source crossing the filter carries its own alert pair; the matching triangles ship disabled because the sharp cutoff rings after gaps and impulse bars. - **Dashboard**: reports the realized order and section split, the passband edge with its ripple, and the derived stopband edge. The gap between the edges is the transition band the design minimizes. ## Elliptic Filter Settings - **Source** (default close): series the filter smooths. - **Cutoff Period** (default 20): passband edge in bars. Slower swings are kept within the ripple bound. - **Order** (default 4): number of poles; higher narrows the transition band but deepens post-impulse ringing. - **Passband Ripple (dB)** (default 0.5): bounded amplitude wobble allowed in kept wavelengths; more ripple buys a sharper cutoff. - **Stopband Attenuation (dB)** (default 40): floor to which rejected wavelengths are held. - **Show Dashboard** (on) with **Location** (Top Right) and **Size** (Small); style: **Line Coloring** (Directional), **Line Width** (2), **Crossing Markers** (off). ## Frequently Asked Questions ### Elliptic or Butterworth: which smoother should I pick? The [Butterworth Filter](https://www.luxalgo.com/library/indicator/butterworth-filter/) is maximally flat: no ripple anywhere, at the cost of the slowest cutoff of the classical designs. The elliptic is the opposite corner: sharpest transition for the order, paid for with bounded ripple in both bands and stronger ringing. ### Why does the line wiggle after a gap? Ringing: a sharp frequency cutoff necessarily oscillates after an impulsive input, so a gap or news bar leaves decaying wiggles that are filter artifacts, not price structure. Lower orders soften the effect. ### What is the stopband edge on the dashboard? The derived longest wavelength already attenuated by the full stopband depth. It is not set directly. It follows from the four targets, so it shows what a settings change actually did. ## Related indicators - [Chebyshev Filters](https://www.luxalgo.com/library/indicator/chebyshev-filters/) (Trend): markdown at https://www.luxalgo.com/library/indicator/chebyshev-filters.md - [Laguerre Filter](https://www.luxalgo.com/library/indicator/laguerre-filter/) (Trend): markdown at https://www.luxalgo.com/library/indicator/laguerre-filter.md - [Gaussian Filter](https://www.luxalgo.com/library/indicator/gaussian-filter/) (Trend): markdown at https://www.luxalgo.com/library/indicator/gaussian-filter.md - [Swiss Army Knife Filter](https://www.luxalgo.com/library/indicator/swiss-army-knife-filter/) (Trend): markdown at https://www.luxalgo.com/library/indicator/swiss-army-knife-filter.md - [Ehlers SuperSmoother](https://www.luxalgo.com/library/indicator/ehlers-supersmoother/) (Trend): markdown at https://www.luxalgo.com/library/indicator/ehlers-supersmoother.md - [Ehlers Instantaneous Trendline](https://www.luxalgo.com/library/indicator/ehlers-instantaneous-trendline/) (Trend): markdown at https://www.luxalgo.com/library/indicator/ehlers-instantaneous-trendline.md - [Whittaker Envelope](https://www.luxalgo.com/library/indicator/whittaker-envelope/) (Whittaker–Henderson Smoother): markdown at https://www.luxalgo.com/library/indicator/whittaker-envelope.md - [Percentile Nearest Rank Using Arrays](https://www.luxalgo.com/library/indicator/percentile-nearest-rank-using-arrays/) (Order-statistic Filters): markdown at https://www.luxalgo.com/library/indicator/percentile-nearest-rank-using-arrays.md --- Source: https://www.luxalgo.com/library/indicator/elliptic-filter/ (LuxAlgo Library). Free to use with attribution: https://www.luxalgo.com/library/license/