highcharts/es-modules/indicators/williams-r.src.js

JavaScript charting framework

/* *
 *
 *  License: www.highcharts.com/license
 *
 * */

'use strict';

import H from '../parts/Globals.js';
import '../parts/Utilities.js';
import reduceArrayMixin from '../mixins/reduce-array.js';

var isArray = H.isArray,
    getArrayExtremes = reduceArrayMixin.getArrayExtremes;

/**
 * The Williams %R series type.
 *
 * @private
 * @class
 * @name Highcharts.seriesTypes.williamsr
 *
 * @augments Highcharts.Series
 */
H.seriesType(
    'williamsr',
    'sma',
    /**
     * Williams %R. This series requires the `linkedTo` option to be
     * set and should be loaded after the `stock/indicators/indicators.js`.
     *
     * @sample {highstock} stock/indicators/williams-r
     *         Williams %R
     *
     * @extends      plotOptions.sma
     * @since        7.0.0
     * @product      highstock
     * @excluding    allAreas, colorAxis, joinBy, keys, navigatorOptions,
     *               pointInterval, pointIntervalUnit, pointPlacement,
     *               pointRange, pointStart, showInNavigator, stacking
     * @optionparent plotOptions.williamsr
     */
    {
        /**
         * Paramters used in calculation of Williams %R series points.
         * @excluding index
         */
        params: {
            /**
             * Period for Williams %R oscillator
             */
            period: 14
        }
    },
    /**
     * @lends Highcharts.Series#
     */
    {
        nameBase: 'Williams %R',
        getValues: function (series, params) {
            var period = params.period,
                xVal = series.xData,
                yVal = series.yData,
                yValLen = yVal ? yVal.length : 0,
                WR = [], // 0- date, 1- Williams %R
                xData = [],
                yData = [],
                slicedY,
                close = 3,
                low = 2,
                high = 1,
                extremes,
                R,
                HH, // Highest high value in period
                LL, // Lowest low value in period
                CC, // Current close value
                i;

            // Williams %R requires close value
            if (
                xVal.length < period ||
                !isArray(yVal[0]) ||
                yVal[0].length !== 4
            ) {
                return false;
            }

            // For a N-period, we start from N-1 point, to calculate Nth point
            // That is why we later need to comprehend slice() elements list
            // with (+1)
            for (i = period - 1; i < yValLen; i++) {
                slicedY = yVal.slice(i - period + 1, i + 1);
                extremes = getArrayExtremes(slicedY, low, high);

                LL = extremes[0];
                HH = extremes[1];
                CC = yVal[i][close];

                R = ((HH - CC) / (HH - LL)) * -100;

                if (xVal[i]) {
                    WR.push([xVal[i], R]);
                    xData.push(xVal[i]);
                    yData.push(R);
                }
            }

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

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