AlgoTradeSoft

Bollinger Bands (SDK Trading)

A Bollinger Bands indicator is a technical analysis indicator defined by a set of lines plotted two(or more) standard deviations (positively and negatively) away from a simple moving average (SMA) of the prices to show the volatility of a commodity or financial instrument. It can be customized or adjusted to user preferences.

Bollinger Bands (SDK Trading)

registerIndicator("bands", "Bollinger Bands(v1.0)", function (context) {
    var dataInput = getDataInput(context, 0)
    var dataOutput = getDataOutput(context, "ma")
    var dataOutputUpper = getDataOutput(context, "upper")
    var dataOutputLower = getDataOutput(context, "lower")

    var method = getIndiParameter(context, "method")
    var period = getIndiParameter(context, "period")
    var deviations = getIndiParameter(context, "deviations")
    var shift = getIndiParameter(context, "shift")

    var calculatedLength = getCalculatedLength(context)

    if ("smma" == method) {
        smma(dataInput, dataOutput, calculatedLength, period)
    } else if("ema" == method) {
        ema(dataInput, dataOutput, calculatedLength, period)
    } else if ("lwma" == method) {
        lwma(dataInput, dataOutput, calculatedLength, period)
    } else {
        sma(dataInput, dataOutput, calculatedLength, period)
    }

    var ptr = null
    var ptr2 = null

    if (calculatedLength > 0) {
        ptr = calculatedLength - 1
    } else {
        for (var i = 0; i < period - 1; i++) {
            dataOutputUpper[i] = 0
            dataOutputLower[i] = 0
        }

        ptr = period - 1
    }

    var devVal, sum, midVal, tmp

    while (ptr < dataInput.length) {
        sum = 0
        ptr2 = ptr - period + 1
        midVal = dataOutput[ptr]
        while (ptr2 <= ptr) {
            tmp = dataInput[ptr2] - midVal
            sum += tmp * tmp
            ptr2++
        }
        devVal = deviations * Math.sqrt(sum / period)
        dataOutputUpper[ptr] = midVal + devVal
        dataOutputLower[ptr] = midVal - devVal

        ptr++
    }

    if (calculatedLength == 0) {
        setIndiShift(context, "ma", shift)
        setIndiShift(context, "upper", shift)
        setIndiShift(context, "lower", shift)
    }
},[{
    name: "period",
    value: 5,
    required: true,
    type: PARAMETER_TYPE.INTEGER,
    range: [1, 100]
},{
    name: "deviations",
    value: 2.0,
    required: true,
    type: PARAMETER_TYPE.NUMBER,
    range: [0, 10]
},{
    name: "shift",
    value: 0,
    required: true,
    type: PARAMETER_TYPE.INTEGER,
    range: [-30, 30]
},{
    name: "method",
    value: "sma",
    required: true,
    type: PARAMETER_TYPE.STRING
}],
[{
    name: DATA_NAME.CLOSE,
    index: 0
}],
[{
    name: "ma",
    visible: true,
    renderType: RENDER_TYPE.LINE,
    color: "steelblue"
},{
    name: "upper",
    visible: true,
    renderType: RENDER_TYPE.DASHARRAY,
    color: "steelblue"
},{
    name: "lower",
    visible: true,
    renderType: RENDER_TYPE.DASHARRAY,
    color: "steelblue"
}],
WHERE_TO_RENDER.CHART_WINDOW)