This ProBuilder code snippet is designed to detect and plot rectangular zones in a price chart that fall within a specified percentage deviation over a given period. These zones can help in identifying areas of price consolidation or stability.

percent = 0.3 //max percent deviation
period = 20 //period of lookback
minBar = 3 //minimal bar for the boxes
count=0
hh=0
ll=close*10
for i = period-1 downto 0 do
    dev=abs(close[i+1]-close[i])/close[i+1]
    if dev<=percent/100 then
        //drawarrow(barindex[i],close[i])
        count=count+1
        hh=max(hh,high[i])
        ll=min(ll,low[i])
        if count=1 then
            startbar=barindex[i]
        else
            endbar=barindex[i]
        endif
    else
        break
    endif
next
if count>=minBar then
    drawrectangle(startbar,ll,endbar,hh)
endif
return //(close-close[1])/close,percent/100,count,highll,dev

This code snippet operates by evaluating the price changes between consecutive bars and checking if these changes stay within a defined percentage deviation. If the deviation is within the acceptable range for a sufficient number of consecutive bars, a rectangle is drawn to highlight this zone.

• Initialization: Variables such as percent, period, and minBar are set to define the maximum percentage deviation, the lookback period, and the minimum number of bars for a valid zone, respectively.
• Loop through bars: The code iterates backwards through the bars from the most recent to the start of the defined period. For each bar, it calculates the deviation of the closing price from the previous bar’s closing price.
• Check deviation: If the deviation is less than or equal to the specified percentage, the high and low values are updated to find the maximum and minimum prices in this range, and the count of consecutive bars within the deviation limit is incremented.
• Rectangle plotting: If the count of bars that meet the deviation criteria reaches the minimum bar threshold, a rectangle is drawn from the start to the end of this range, using the highest and lowest prices encountered.
• Breaking the loop: If a bar’s price deviation exceeds the specified percentage, the loop breaks, and no further bars are checked.

This approach is useful for highlighting periods of low volatility or consolidation, which can be significant in various trading strategies.