I was curious to see what Pine uses to accumulate numbers. It looks like it uses the simple "add em up" approach, rather than a compensated summation. This means that especially for large numbers, there is an inherent error amount.
This script implements the Kahan Summation Algorithm, also known as compensated summation.
This is part 2 of my...
While trying to figure out how to make the STDEV function use an exponential moving average instead of simple moving average , I discovered the builtin function doesn't really use either.
Check it out, it's amazing how different the two-pass algorithm is from the builtin!
Eventually I reverse-engineered and discovered that STDEV uses the Naiive algorithm and...