cmo(src, len, _id) {
        let id = this._tsid(_id, `cmo(${len})`)
        let mom = this.change(src, 1, id)

        let g = this.ts(mom[0] >= 0 ? mom[0] : 0.0, id+"g", src.__tf__)
        let l = this.ts(mom[0] >= 0 ? 0.0 : -mom[0], id+"l", src.__tf__)

        let sm1 = this.sum(g, len, id+'1')[0]
        let sm2 = this.sum(l, len, id+'2')[0]

        return this.ts(100 * (sm1 - sm2) / (sm1 + sm2), id, src.__tf__)
    }
Chande Momentum Oscillator
@param {TS} src - Input
@param {number} len - Length
@return {TS} - New time-series