Understanding barstate.isnew Function in Pine Script

Introduction

The barstate.isnew function is pivotal in scripts that require action at the beginning of a new bar on the chart. We will explore its application through examples, ensuring a deep understanding of its use and benefits.

What is barstate.isnew?

Definition and Basic Use

In Pine Script, barstate.isnew is a boolean variable that returns true if the script is executing on the first tick of a new bar. This feature is essential for strategies or studies where specific calculations or actions need to be performed only once per bar.

Syntax

if barstate.isnew 
// Your code here

Example: Implementing barstate.isnew

Let’s create a simple script that utilizes barstate.isnew to calculate and plot a moving average only once per bar.

Code Example

//@version=5
indicator("My Moving Average with barstate.isnew", overlay=true)

length = input(14, "Moving Average Length")
price = close
var float myMovingAvg = na

if barstate.isnew
    myMovingAvg := ta.sma(price, length)

plot(myMovingAvg, "Moving Average", color=color.blue)

Explanation of the Code

1. Indicator Declaration: //@version=5 indicator("My Moving Average with barstate.isnew", overlay=true)
   • Sets the script version and declares a new indicator with the title “My Moving Average with barstate.isnew”. overlay=true allows the plot to be drawn directly on the price chart.
2. Inputs and Variables:length = input(14, "Moving Average Length") price = close var float myMovingAvg = na
   • length is the period of the moving average, set to 14 by default.
   • price uses the closing price of the bar.
   • myMovingAvg is a variable to store the moving average value, initialized as na (not available).
3. Using barstate.isnew:if barstate.isnew myMovingAvg := ta.sma(price, length)
   • This block updates myMovingAvg with the simple moving average (ta.sma) of the price over the specified length, but only at the beginning of a new bar.
4. Plotting the Moving Average:plot(myMovingAvg, "Moving Average", color=color.blue)
   • The plot function draws the moving average on the chart with the label “Moving Average” in blue color.

Key Features and Takeaways

• Function Utility: barstate.isnew is ideal for scenarios where calculations are required only once per bar, optimizing script performance.
• Syntax and Application: The function is straightforward, using a simple if condition to check for a new bar.
• Versatility: It can be applied in various contexts, such as indicators, strategies, or custom calculations.

In conclusion, barstate.isnew in Pine Script Version 5 is a valuable tool for script optimization and precise calculations. Its correct implementation can significantly enhance the performance and accuracy of trading scripts.