Studies

Enable studies for the built-in catalogue and IndicatorFactory. The Indicator trait, IndicatorValue, CustomIndicator and IndicatorRegistry are also available in the headless engine.

Attach a built-in study

Pass an EMA to Chart::add_indicator:

use egui_charts::{Chart, model::BarData};
use egui_charts::studies::EMA;

let mut chart = Chart::new(BarData::new());
let study = chart.add_indicator(Box::new(EMA::new(20)));

The returned id identifies the study’s series. The chart manages recalculation when source bars change and places overlays or separate panes according to the indicator. Built-in implementations and their definitions are listed in the API reference.

Write a custom study

CustomIndicator accepts a Send + Sync calculation closure. Return one value per source bar and use IndicatorValue::None during warm-up or when input is unavailable. The builder guide includes a complete one-bar-change example. Implement Indicator directly for incremental calculation; studies::helpers and Stepper support reusable scalar operations.

Supply additional data

Some studies need another interval, another symbol, instrument metrics or actual executions. A connected feed loads declared study data; direct hosts answer Chart::study_data_requests with set_study_data. Read calendar and viewport studies for intrabar requirements and missing values, and order flow for event-driven inputs.

The host may evaluate scripts and expose their results through a custom study. The library does not provide a scripting runtime.