Pine Script技术问询：仅显示最新2条枢轴线（计数器实现方案）

Yep, using a counter (plus array tracking for line objects) is a perfect solution to avoid cluttering your chart with old pivot lines. Below’s a modified version of your Pine Script code that lets you specify how many recent pivot line sets to keep (1 or 2, as you requested):

Modified Full Code #

study("Pivot Points Standard", shorttitle="Pivots Std", overlay=true)

// Let user specify how many latest line sets to keep (1-2, or more if needed)
keepLines = input.int(2, minval=1, maxval=5, title="Number of Latest Pivot Line Sets to Keep")

// Determine higher timeframe logic (unchanged from original)
higherTF = iff(timeframe.isminutes,iff(timeframe.period == "15", "D", "W"), iff(timeframe.isdaily, "M", "12M"))
prevCloseHTF = security(syminfo.tickerid, higherTF, close[1], lookahead=true)
prevOpenHTF = security(syminfo.tickerid, higherTF, open[1], lookahead=true)
prevHighHTF = security(syminfo.tickerid, higherTF, high[1], lookahead=true)
prevLowHTF = security(syminfo.tickerid, higherTF, low[1], lookahead=true)

// Calculate pivot levels (unchanged from original)
pLevel = (prevHighHTF + prevLowHTF + prevCloseHTF) / 3
r1Level = pLevel * 2 - prevLowHTF
s1Level = pLevel * 2 - prevHighHTF

// Arrays to track all created line objects (one array per line type)
var line[] r1Lines = array.new_line()
var line[] pLines = array.new_line()
var line[] s1Lines = array.new_line()
var int lineCount = 0 // Counter for number of line sets created

// Only create new lines when pivot levels change (prevents duplicate lines)
if pLevel[1] != pLevel
    // If we've exceeded the number of lines to keep, delete the oldest set
    if lineCount >= keepLines
        // Remove and delete the oldest R1, P, S1 lines
        line.delete(array.shift(r1Lines))
        line.delete(array.shift(pLines))
        line.delete(array.shift(s1Lines))
        lineCount := lineCount - 1
    
    // Create new line set for current pivot levels
    newR1 = line.new(bar_index, r1Level, bar_index, r1Level, extend=extend.none)
    newP = line.new(bar_index, pLevel, bar_index, pLevel, width=3, extend=extend.none, color=color.blue)
    newS1 = line.new(bar_index, s1Level, bar_index, s1Level, extend=extend.none)
    
    // Add new lines to our arrays and increment counter
    array.push(r1Lines, newR1)
    array.push(pLines, newP)
    array.push(s1Lines, newS1)
    lineCount := lineCount + 1

    // Add labels for the new pivot levels (optional)
    label.new(bar_index, r1Level, "R1", style=label.style_none)
    label.new(bar_index, pLevel, "P", style=label.style_none)
    label.new(bar_index, s1Level, "S1", style=label.style_none)

// Extend all active lines to the current bar (keeps lines updated as new bars form)
if barstate.islast
    for i = 0 to array.size(r1Lines)-1
        line.set_x2(array.get(r1Lines, i), bar_index)
        line.set_x2(array.get(pLines, i), bar_index)
        line.set_x2(array.get(s1Lines, i), bar_index)

Key Changes Explained #

• User-Controlled Line Count: The keepLines input lets you easily switch between keeping 1 or 2 (or more) recent pivot line sets—just adjust the slider in the settings panel.
• Array Tracking: We use arrays (r1Lines, pLines, s1Lines) to store every line object we create. This lets us precisely target and delete the oldest lines when we hit our limit.
• Counter Logic: The lineCount variable tracks how many line sets we’ve created. When it exceeds keepLines, we use array.shift() to remove the oldest line from each array and line.delete() to erase it from the chart.
• Clean Line Extension: The final loop ensures all active lines extend to the latest bar, so your pivot levels stay visible as new price action occurs.

内容的提问来源于stack exchange，提问作者Erwin Blumenhagen