text: // Keltner Channels
  var keltnerchannel = require('keltnerchannel').kc
  module.exports = function kc (s, key, length, source_key) {
    if (!source_key) source_key = 'close'
    if (s.lookback.length > length) {
      let data = []
      for (var i=length-1; i>=0; i--) {
        data.push({
          high: s.lookback[i].high,
          low: s.lookback[i].low,
          close: s.lookback[i].close
        })
      }
      let result = keltnerchannel(data, s.kc_options.kc_size, s.kc_options.kc_multiplier)
      s.period[key] = result
    }
  }
  
  