This ProBuilder script generates a heatmap that visualizes the frequency of price touches within a specified range and period on a trading chart. The heatmap’s color intensity increases with the frequency of price touches, providing a visual representation from black to red.

defparam drawonlastbaronly=true
Period = 120
step = 0.25

hh = Highest[Period](High)
ll = Lowest[Period](Low)
checkprice = ll

if islastbarupdate then
  ind=0 //reset index of array

  //get the price touch occurrences for each level
  while checkprice<=hh do
    touch=0 //reset price touch for this price level
    for i = 0 to period-1 do
      if high[i]>=checkprice and low[i]<=checkprice then
        touch=touch+1
    $hm[ind] = touch
    endif
    next

    //define color
    r = min($hm[ind]*10,255)

    //plot the result
    //drawtext($hm[ind],barindex+5,checkprice) coloured(r,0,0)
    drawtext("█",barindex+5,checkprice) coloured(r,0,0)
    checkprice=checkprice+step //increase price check for next round
    ind=ind+1 //increase array index
  wend
endif

return hh,ll

This script is designed to run on the last bar of the chart only, to ensure performance and relevance of the displayed data. Here's a breakdown of how the code works:

• Initialization: Sets the script to execute only on the last bar and defines the period and step for the price range.
• Calculating High and Low: Determines the highest and lowest prices over the specified period to set the range for the heatmap.
• Heatmap Calculation: Iterates through each price level between the lowest and highest prices. For each level, it checks how many times the price has touched this level within the period.
• Color Assignment: Assigns a color based on the frequency of touches. The color intensity (red component) increases with more touches, capped at a maximum value of 255.
• Display: Uses a colored block character to visually represent the frequency at each price level on the chart.
• Index Management: Manages an array index to store and retrieve the number of touches for each price level.

This heatmap can be a useful tool for traders to visualize significant price levels where the market has shown repeated interest over a given period.