dpo.src.js 3.82 KB
/* *
 *
 *  License: www.highcharts.com/license
 *
 * */

'use strict';

import H from '../parts/Globals.js';

var correctFloat = H.correctFloat,
    pick = H.pick;

// Utils
function accumulatePoints(sum, yVal, i, index, subtract) {
    var price = pick(yVal[i][index], yVal[i]);

    if (subtract) {
        return correctFloat(sum - price);
    }
    return correctFloat(sum + price);
}

/**
 * The DPO series type.
 *
 * @private
 * @class
 * @name Highcharts.seriesTypes.dpo
 *
 * @augments Highcharts.Series
 */
H.seriesType(
    'dpo',
    'sma',
    /**
     * Detrended Price Oscillator. This series requires the `linkedTo` option to
     * be set and should be loaded after the `stock/indicators/indicators.js`.
     *
     * @sample {highstock} stock/indicators/dpo
     *         Detrended Price Oscillator
     *
     * @extends      plotOptions.sma
     * @since        7.0.0
     * @product      highstock
     * @excluding    allAreas, colorAxis, compare, compareBase, joinBy, keys,
     *               navigatorOptions, pointInterval, pointIntervalUnit,
     *               pointPlacement, pointRange, pointStart, showInNavigator,
     *               stacking
     * @optionparent plotOptions.dpo
     */
    {
        /**
         * Parameters used in calculation of Detrended Price Oscillator series
         * points.
         */
        params: {
            /**
             * Period for Detrended Price Oscillator
             */
            period: 21
        }
    },
    /**
     * @lends Highcharts.Series#
     */
    {
        nameBase: 'DPO',
        getValues: function (series, params) {
            var period = params.period,
                index = params.index,
                offset = Math.floor(period / 2 + 1),
                range = period + offset,
                xVal = series.xData || [],
                yVal = series.yData || [],
                yValLen = yVal.length,
                DPO = [], // 0- date, 1- Detrended Price Oscillator
                xData = [],
                yData = [],
                sum = 0,
                oscillator,
                periodIndex,
                rangeIndex,
                price,
                i,
                j;

            if (xVal.length <= range) {
                return false;
            }

            // Accumulate first N-points for SMA
            for (i = 0; i < period - 1; i++) {
                sum = accumulatePoints(sum, yVal, i, index);
            }

            // Detrended Price Oscillator formula:
            // DPO = Price - Simple moving average [from (n / 2 + 1) days ago]

            for (j = 0; j <= yValLen - range; j++) {
                periodIndex = j + period - 1;
                rangeIndex = j + range - 1;

                // adding the last period point
                sum = accumulatePoints(sum, yVal, periodIndex, index);
                price = pick(yVal[rangeIndex][index], yVal[rangeIndex]);

                oscillator = price - sum / period;

                // substracting the first period point
                sum = accumulatePoints(sum, yVal, j, index, true);

                DPO.push([xVal[rangeIndex], oscillator]);
                xData.push(xVal[rangeIndex]);
                yData.push(oscillator);
            }

            return {
                values: DPO,
                xData: xData,
                yData: yData
            };
        }
    }
);

/**
 * A Detrended Price Oscillator. If the [type](#series.dpo.type) option is not
 * specified, it is inherited from [chart.type](#chart.type).
 *
 * @extends   series,plotOptions.dpo
 * @since     7.0.0
 * @product   highstock
 * @excluding allAreas, colorAxis, compare, compareBase, dataParser, dataURL,
 *            joinBy, keys, navigatorOptions, pointInterval, pointIntervalUnit,
 *            pointPlacement, pointRange, pointStart, showInNavigator, stacking
 * @apioption series.dpo
 */