如何将Pine Script指标1标签的bar偏移量作为指标2的回归通道长度输入？

需求说明：

• 指标1：识别lowLB周期内的最低点，在对应K线位置绘制标签显示价格
• 指标2：回归通道指标，需要将指标1中最低点所在K线与当前K线的间隔数量作为lengthInput参数

原指标代码 #

指标1（最低点标签）

//@version=5
indicator("Test", "", true)

lowLB = input(20, "Low Lookback")

lo = ta.lowest(lowLB)
lowestBarOffset = - ta.lowestbars(lowLB)

// Create label on bar zero only.
var lbl = label.new(na, na, "", color = color.rgb(190, 190, 190), style=label.style_label_upper_right)
// When a new low is found, move the label there and update its text and tooltip.
if ta.change(lo)
    // Build label and tooltip strings.
    labelText = "Low: " + str.tostring(lo, format.mintick)
    tooltipText = "Offest in bars: " + str.tostring(lowestBarOffset) + "\nLow: " + str.tostring(low[lowestBarOffset], format.mintick)
    // Update the label's position, text and tooltip.
    label.set_xy(lbl, bar_index[lowestBarOffset], lo)
    label.set_text(lbl, labelText)
    label.set_tooltip(lbl, tooltipText)

指标2（回归通道片段）

lengthInput = input(<INPUT_FROM_FUNCTION_1>, title="Length")    <------- ?
sourceInput = input.source(close, title="Source")

group1 = "Channel Settings"
useUpperDevInput = input.bool(true, title="Upper Deviation", inline = "Upper Deviation", group = group1)
upperMultInput = input.float(2.0, title="", inline = "Upper Deviation", group = group1) 
.....

解决方案 #

不需要使用barstate，核心是跟踪最新最低点的K线索引，再计算其与当前K线的间隔。

关键步骤

1. 新增变量存储最新最低点的K线索引：用var关键字定义，确保只初始化一次，每次找到新低点时更新
2. 计算间隔数：用当前K线索引减去存储的低点K线索引，得到两者的间隔
3. 处理初始值：未找到低点时，给lengthInput设置默认值（比如用lowLB）

整合后的完整代码

//@version=5
indicator("Low-Based Regression Channel", "", true)

// --- 指标1：最低点标签模块 ---
lowLB = input(20, "Low Lookback")

lo = ta.lowest(lowLB)
lowestBarOffset = - ta.lowestbars(lowLB)

// 存储最新最低点的bar索引（用var保持状态）
var int lowestBarIndex = na
// 找到新低点时更新索引
if ta.change(lo)
    lowestBarIndex := bar_index[lowestBarOffset]
    // 更新标签逻辑（保留原代码）
    var lbl = label.new(na, na, "", color = color.rgb(190, 190, 190), style=label.style_label_upper_right)
    labelText = "Low: " + str.tostring(lo, format.mintick)
    tooltipText = "Offest in bars: " + str.tostring(lowestBarOffset) + "\nLow: " + str.tostring(low[lowestBarOffset], format.mintick)
    label.set_xy(lbl, lowestBarIndex, lo)
    label.set_text(lbl, labelText)
    label.set_tooltip(lbl, tooltipText)

// --- 指标2：回归通道模块 ---
// 计算间隔数，初始未找到低点时用lowLB作为默认值
lengthInput = na(lowestBarIndex) ? lowLB : bar_index - lowestBarIndex
// 可选：保留手动输入开关，让用户切换自动/手动模式
// useAutoLength = input.bool(true, "Use Auto Length from Lowest Bar")
// manualLength = input.int(20, "Manual Length")
// lengthInput = useAutoLength ? (na(lowestBarIndex) ? lowLB : bar_index - lowestBarIndex) : manualLength

sourceInput = input.source(close, title="Source")

group1 = "Channel Settings"
useUpperDevInput = input.bool(true, title="Upper Deviation", inline = "Upper Deviation", group = group1)
upperMultInput = input.float(2.0, title="", inline = "Upper Deviation", group = group1)

// 回归通道核心逻辑（补充完整你的原有代码）
// 示例：线性回归计算
linReg = ta.linreg(sourceInput, lengthInput, 0)
dev = ta.stdev(sourceInput, lengthInput)
upperChannel = useUpperDevInput ? linReg + upperMultInput * dev : na
plot(upperChannel, color=color.new(color.blue, 0), title="Upper Channel")
plot(linReg, color=color.new(color.orange, 0), title="Mid Line")

代码说明

• var int lowestBarIndex = na：持久化存储最新低点的K线索引，避免每次K线刷新重置
• lengthInput = na(lowestBarIndex) ? lowLB : bar_index - lowestBarIndex：处理初始状态，未找到低点时用lowLB作为默认长度，找到后自动计算间隔
• 可选的手动输入开关：如果需要允许用户切换自动/手动长度，取消注释对应代码即可

内容的提问来源于stack exchange，提问作者NoPants