The equation is Green + Red + = Total Candles; where total candles = length
When calculating the allocation part, the candles are subtracted from the sum of green and red, and the new value is divided by the length period.
For example, the green line = (sum of all green candles - / 2) / length; the reason to divide by 2 is to eliminate the redundancy it can cause.
When the green line crosses above the red line, the number of green candles is more than red in the defined length period. Similarly, when the red line crossed above the green, there were more red candles than green in that period.
The line shows if any or near candles have appeared. It acts as a form of resistance against the green and red candles.
There's also the option to change the value of the doji's weight. Default is at 0.1.
The indicator does not show trend nor momentum, even though it may replicate some of its behavior from time to time. It is purely showing the allocation of the number of candles classified as green, red, and within the length provided.
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.