/*
计算方法：
1、MA的N日收盘价加总/N
2、DPO = 收盘价 - ((n / 2) + 1)日的MA
3、MADPO = DPO M日的移动平均
N  = 21， M = 6
*/

// 指标算法
function DPO(r, n) {
    var arrDpo = []
    for (var i = 0 ; i < r.length ; i++) {
        var currRecords = []
        for (var j = 0 ; j < i ; j++) {
            currRecords.push(r[j])
        }
        var ma = TA.MA(currRecords, (_N(n / 2, 0) + 1))
        var dpo = NaN
        if (currRecords.length == 0 || !ma || ma.length == 0 || !ma[ma.length - 1]) {
            dpo = NaN
        } else {
            var close = r[i].Close
            dpo = close - ma[ma.length - 1]        
        }
        arrDpo.push(dpo)
    }
    return arrDpo
}

function MADPO(dpo, m) {
    return TA.MA(dpo, m)
}

// 使用指标例子
function main() {
    var r = exchange.GetRecords()
    var dpo = DPO(r, 21)
    Log(_D(r[r.length - 1].Time), "dpo on last bar:", dpo[dpo.length - 1])
    Log(_D(r[r.length - 2].Time), "dpo on pre bar:", dpo[dpo.length - 2])
    
    var madpo = MADPO(dpo, 6)
    Log(_D(r[r.length - 1].Time), "madpo on last bar:", madpo[madpo.length - 1])
    Log(_D(r[r.length - 2].Time), "madpo on pre bar:", madpo[madpo.length - 2])
}

给你个思路，不保证对，没验证过。