Multiple-Timeframe Keltner Channel

Keltner Channels are volatility-based envelopes set above and below a moving average first devised by Chester W. Keltner then later revised by Linda Bradford Raschke.
This script allows for the overlay of the Keltner Channel across multiple-timeframes.
Additionally allows for the selection of the true range average type with a user defined lookback period.
Default settings is the traditional type of KC seen on TV.

Note: When inputting the MA-Basis strings it is case sensitive; enter only lowercase or all uppercase. If a typo is made it will by default revert to an EMA base.