@react-financial-charts/indicators/src/calculator/heikinAshi.ts

Indicators for react-financial-charts

import { mappedSlidingWindow } from "../utils";

export default function () {
    let source = (x: any) => x;

    const calculator = (data: any[]) => {
        const algorithm = mappedSlidingWindow()
            .windowSize(2)
            .undefinedValue(
                ({ open, high, low, close }: { open: number; high: number; low: number; close: number }) => {
                    close = (open + high + low + close) / 4;
                    return { open, high, low, close };
                },
            )
            .accumulator(([prev, now]: any) => {
                const { date, volume } = now;
                const close = (now.open + now.high + now.low + now.close) / 4;
                const open = (prev.open + prev.close) / 2;
                const high = Math.max(open, now.high, close);
                const low = Math.min(open, now.low, close);
                return { date, open, high, low, close, volume };
            });

        return algorithm(data);
    };

    calculator.source = (newSource?: any) => {
        if (newSource === undefined) {
            return source;
        }

        source = newSource;

        return calculator;
    };

    return calculator;
}