This is our first video session on "Thinking in Pine" series. Before we start, we want to explain a bit about our new initiative.
🎲 What is "Thinking in Pine"?
In our journey to empower the trading community, we're excited to introduce "Thinking in Pine," a series of concise, 5-10 minute videos dedicated to unraveling the complexities of Pine Script®. We have our own list of topics to be covered, and we will start releasing the videos one by one. However, if you're grappling with any aspect of Pine Script® or stuck on an implementation, we encourage you to reach out to us or drop a comment here. We aim to address your queries by breaking down challenging concepts or implementations into easily digestible content.
What kind of videos are covered in "Thinking in Pine"?
- Pine Script® Focus: We try to keep our focus on Pine Script® concepts and implementations.
- General Utility: We prioritize topics that offer broader learning value. Though it's challenging to quantify this, we'll use our judgment to select topics that benefit the wider audience.
- Time-Efficient Demonstrations: Ideally, we want to keep our demonstrations to 5–10 mins of time.
We're here to demystify Pine Script®, one topic at a time, making it accessible for everyone from beginners to advanced users. Stay tuned for insightful sessions with "Thinking in Pine"!
🎲 Demonstrating var, varip and regular variables in Pine Script®
In this video, we have demonstrated the difference between var, varip and regular variables by using an example implementation of OBV indicator.
🎯 Logic of OBV Calculation
- Start with the value 0
- On each bar, add volume to the indicator if close price is higher than previous bar close price.
- On each bar, remove volume from the indicator is close price is lesser than previous bar close price
🎯 Highlights
- Regular variables are initialized separately on each bar and does not propagate value to next bar unless coded to do it.
- var variables are initialized once and then can be reassigned any number of times using := operator. The variables declared as var will propagate the current values to the next bar.
- varip variables are initialized once and then can be reassigned any number of times using := operator. varip will behave similar to var on historical bars. However, on real time bars, they are recalculated on every tick, and they remember the state of each tick.
🎯 Example Program Used
Here is the example program used in the demonstration.
//Plot built-in OBV value for reference
plot(ta.obv, "OBV Built In", color=color.yellow)
//Volume multiplied by +-1 based on change in close price compared to previous bar.
volumeBySign = math.sign(nz(ta.change(close), 0))*volume
//Obv calculation by using regular variable. Code need to access and add last bar value using obvByRegular[1]
obvByRegular = 0.0
obvByRegular += nz(obvByRegular[1], 0) + volumeBySign
plot(obvByRegular, "OBV By Regular Variable", color=color.blue)
//Obv calculation using var variable. Since var variables propagate values to next bar,
// we do not need to use historical operator to get the last bar value
var obvByVar = 0.0
obvByVar += volumeBySign
plot(obvByVar, "OBV by var Variable", color = color.maroon)
//Obv implementation using varip. The OBV is calculated based on every tick. Histoical values will match the same as that of other implementation.
//However, in real time, the calculations are done based on the tick values
varip obvByVarip = 0.0
varip lastPrice = close
varip lastVolume = volume
if(barstate.isnew)
lastVolume := 0
obvByVarip += math.sign(close-lastPrice)*(volume-lastVolume)
lastPrice := close
lastVolume := volume
plot(obvByVarip, "OBV by varip Variable", color = color.purple)
🎲 References: