A keltner channel is based on two bands, plotted above and a moving average. It is similar to bollinger bands except it uses Average true range instead of standard deviation. The upper band is a moving average plus some multiple of the Average True Range. The lower band is the moving average minus a multiple of the Average True Range.
Period (Period = 10)
BandMovingAverage=AVERAGE[period](high-low)
MiddleMovingAverage=AVERAGE[period](TypicalPrice)
upperband=MiddleMovingAverage+BandMovingAverage
lowerband=MiddleMovingAverage-BandMovingAverage
DMA= AVERAGE[period](TypicalPrice)
RETURN upperband COLOURED (0,200,0) AS"Keltner Upper Band", lowerband COLOURED (0,200,0) AS"Keltner Lower Band", DMA COLOURED (0,0,255) AS"DMA"