How to calculate the standard deviation in in Pine Script

Question

I just came across pine script now and want to create a simple indicator. I am not a programmer so it’s not native to me.

The code would calculate the average values of the high-low for the last 20 bars. The variable avgRange would be used to store the average. So the function I used to calculate simple moving average was: ta.sma(

I want to calculate the standard deviation of the high-low over each of the last 20 bars. I would name the variable StDev. What function do I use for that? Is it ta.cstd(?

Lastly, I want to find the coefficient of variation(I named the variable CoffVar) and plot it’s value.

So the code I wrote so far is below. I left the standard deviation blank because I don’t know what to fill in there.

BarRange()=>high-low avgRange=ta.sma(BarRange(),20) StDev=……. CoffVar=StDev/avgRange*100 plot(CoffVar)

Answer 1

pine script already has a built in function in the technical analysis library (ta.stdev). you will just need to enter the source (in your case hl2 is the mid point of the bar) and the number of bars:

ta.stdev(hl2, 20)