highcharts
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JavaScript charting framework
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JavaScript
/* *
*
* License: www.highcharts.com/license
*
* !!!!!!! SOURCE GETS TRANSPILED BY TYPESCRIPT. EDIT TS FILE ONLY. !!!!!!!
*
* */
;
import SeriesRegistry from '../../../Core/Series/SeriesRegistry.js';
const { ema: EMAIndicator } = SeriesRegistry.seriesTypes;
import U from '../../../Core/Utilities.js';
const { correctFloat, isArray, merge } = U;
/* *
*
* Class
*
* */
/**
* The DEMA series Type
*
* @private
* @class
* @name Highcharts.seriesTypes.dema
*
* @augments Highcharts.Series
*/
class DEMAIndicator extends EMAIndicator {
/* *
*
* Functions
*
* */
getEMA(yVal, prevEMA, SMA, index, i, xVal) {
return super.calculateEma(xVal || [], yVal, typeof i === 'undefined' ? 1 : i, this.EMApercent, prevEMA, typeof index === 'undefined' ? -1 : index, SMA);
}
getValues(series, params) {
const period = params.period, EMAvalues = [], doubledPeriod = 2 * period, xVal = series.xData, yVal = series.yData, yValLen = yVal ? yVal.length : 0, DEMA = [], xDataDema = [], yDataDema = [];
let accumulatePeriodPoints = 0, EMA = 0,
// EMA(EMA)
EMAlevel2,
// EMA of previous point
prevEMA, prevEMAlevel2,
// EMA values array
i, index = -1, DEMAPoint, SMA = 0;
this.EMApercent = (2 / (period + 1));
// Check period, if bigger than EMA points length, skip
if (yValLen < 2 * period - 1) {
return;
}
// Switch index for OHLC / Candlestick / Arearange
if (isArray(yVal[0])) {
index = params.index ? params.index : 0;
}
// Accumulate first N-points
accumulatePeriodPoints =
super.accumulatePeriodPoints(period, index, yVal);
// First point
SMA = accumulatePeriodPoints / period;
accumulatePeriodPoints = 0;
// Calculate value one-by-one for each period in visible data
for (i = period; i < yValLen + 2; i++) {
if (i < yValLen + 1) {
EMA = this.getEMA(yVal, prevEMA, SMA, index, i)[1];
EMAvalues.push(EMA);
}
prevEMA = EMA;
// Summing first period points for EMA(EMA)
if (i < doubledPeriod) {
accumulatePeriodPoints += EMA;
}
else {
// Calculate DEMA
// First DEMA point
if (i === doubledPeriod) {
SMA = accumulatePeriodPoints / period;
}
EMA = EMAvalues[i - period - 1];
EMAlevel2 = this.getEMA([EMA], prevEMAlevel2, SMA)[1];
DEMAPoint = [
xVal[i - 2],
correctFloat(2 * EMA - EMAlevel2)
];
DEMA.push(DEMAPoint);
xDataDema.push(DEMAPoint[0]);
yDataDema.push(DEMAPoint[1]);
prevEMAlevel2 = EMAlevel2;
}
}
return {
values: DEMA,
xData: xDataDema,
yData: yDataDema
};
}
}
/* *
*
* Static Properties
*
* */
/**
* Double exponential moving average (DEMA) indicator. This series requires
* `linkedTo` option to be set and should be loaded after the
* `stock/indicators/indicators.js`.
*
* @sample {highstock} stock/indicators/dema
* DEMA indicator
*
* @extends plotOptions.ema
* @since 7.0.0
* @product highstock
* @excluding allAreas, colorAxis, compare, compareBase, joinBy, keys,
* navigatorOptions, pointInterval, pointIntervalUnit,
* pointPlacement, pointRange, pointStart, showInNavigator,
* stacking
* @requires stock/indicators/indicators
* @requires stock/indicators/dema
* @optionparent plotOptions.dema
*/
DEMAIndicator.defaultOptions = merge(EMAIndicator.defaultOptions);
SeriesRegistry.registerSeriesType('dema', DEMAIndicator);
/* *
*
* Default Export
*
* */
export default DEMAIndicator;
/* *
*
* API Options
*
* */
/**
* A `DEMA` series. If the [type](#series.dema.type) option is not
* specified, it is inherited from [chart.type](#chart.type).
*
* @extends series,plotOptions.dema
* @since 7.0.0
* @product highstock
* @excluding allAreas, colorAxis, compare, compareBase, dataParser, dataURL,
* joinBy, keys, navigatorOptions, pointInterval, pointIntervalUnit,
* pointPlacement, pointRange, pointStart, showInNavigator, stacking
* @requires stock/indicators/indicators
* @requires stock/indicators/dema
* @apioption series.dema
*/
''; // Adds doclet above to the transpiled file