能否修改RSI指标的绘图范围至-50至100？

已知RSI指标默认绘图范围为0至100，希望将其显示范围拉伸至-50至100，不改变指标本身的波动逻辑，仅调整显示尺度以便更便捷地在RSI线上绘制趋势线。当前使用的Pine Script代码如下：

//@version=5
indicator(title="Relative Strength Index", shorttitle="RSI", format=format.price, precision=2, timeframe="", timeframe_gaps=true)

ma(source, length, type) =>
    switch type
        "SMA" => ta.sma(source, length)
        "Bollinger Bands" => ta.sma(source, length)
        "EMA" => ta.ema(source, length)
        "SMMA (RMA)" => ta.rma(source, length)
        "WMA" => ta.wma(source, length)
        "VWMA" => ta.vwma(source, length)

rsiLengthInput = input.int(14, minval=1, title="RSI Length", group="RSI Settings")
rsiSourceInput = input.source(close, "Source", group="RSI Settings")
maTypeInput = input.string("SMA", title="MA Type", options=["SMA", "Bollinger Bands", "EMA", "SMMA (RMA)", "WMA", "VWMA"], group="MA Settings")
maLengthInput = input.int(50, title="MA Length", group="MA Settings")

up = ta.rma(math.max(ta.change(rsiSourceInput), 0), rsiLengthInput)
down = ta.rma(-math.min(ta.change(rsiSourceInput), 0), rsiLengthInput)
rsi = down == 0 ? 100 : up == 0 ? 0 : 100 - (100 / (1 + up / down))
rsiMA = ma(rsi, maLengthInput, maTypeInput)

rsicolor = rsi > 70 ? color.new(#ff0057, 0) : rsi < 30 ? color.new(#ff0057, 0) : #1056ee

plot(rsi, "RSI", color=rsicolor, linewidth=2, style=plot.style_stepline)
plot(rsiMA, "RSI-based MA", color=color.rgb(120, 206, 255))


OverBought1 = input.int(80, minval=1)
OverBought2 = input.int(90, minval=1)
OverSold1 = input.int(20, minval=1)
OverSold2 = input.int(10, minval=1)


OB1 = hline(OverBought1 , color=color.red, linestyle=hline.style_dashed)
OB2 = hline(OverBought2 , color=color.red, linestyle=hline.style_dashed)
OS1 = hline(OverSold1 , color=color.green, linestyle=hline.style_dashed)
OS2 = hline(OverSold2 , color=color.green, linestyle=hline.style_dashed)

fill(OB1 , OB2, color=color.rgb(255, 82, 82, 80), title="Red Zoon Fill")
fill(OS1 , OS2 , color=color.rgb(76, 175, 79, 80), title="Green Zoon Fill")

可以通过线性区间映射实现需求，核心是保持RSI的波动比例不变，仅将原0-100的数值范围转换为-50-100。具体修改如下：

关键修改点 #

1. RSI值转换：用公式 stretched_rsi = rsi * 1.5 - 50 完成区间映射：
   • 原RSI=0 → 转换后=-50
   • 原RSI=100 → 转换后=100
   • 中间数值按比例缩放，完全保留原波动逻辑
2. 同步调整配套元素：将RSI均线、超买超卖水平线、填充区域全部按相同比例转换，确保视觉对齐。

修改后的完整代码 #

//@version=5
indicator(title="Stretched RSI (-50 to 100)", shorttitle="Stretched RSI", format=format.price, precision=2, timeframe="", timeframe_gaps=true)

ma(source, length, type) =>
    switch type
        "SMA" => ta.sma(source, length)
        "Bollinger Bands" => ta.sma(source, length)
        "EMA" => ta.ema(source, length)
        "SMMA (RMA)" => ta.rma(source, length)
        "WMA" => ta.wma(source, length)
        "VWMA" => ta.vwma(source, length)

rsiLengthInput = input.int(14, minval=1, title="RSI Length", group="RSI Settings")
rsiSourceInput = input.source(close, "Source", group="RSI Settings")
maTypeInput = input.string("SMA", title="MA Type", options=["SMA", "Bollinger Bands", "EMA", "SMMA (RMA)", "WMA", "VWMA"], group="MA Settings")
maLengthInput = input.int(50, title="MA Length", group="MA Settings")

// 计算原始RSI
up = ta.rma(math.max(ta.change(rsiSourceInput), 0), rsiLengthInput)
down = ta.rma(-math.min(ta.change(rsiSourceInput), 0), rsiLengthInput)
rsi = down == 0 ? 100 : up == 0 ? 0 : 100 - (100 / (1 + up / down))

// 核心：将RSI从0-100映射到-50-100
stretched_rsi = rsi * 1.5 - 50
// 同步转换RSI均线
stretched_rsiMA = ma(stretched_rsi, maLengthInput, maTypeInput)

// 保留原颜色逻辑（基于原始RSI值判断）
rsicolor = rsi > 70 ? color.new(#ff0057, 0) : rsi < 30 ? color.new(#ff0057, 0) : #1056ee

// 绘制转换后的RSI和均线
plot(stretched_rsi, "Stretched RSI", color=rsicolor, linewidth=2, style=plot.style_stepline)
plot(stretched_rsiMA, "Stretched RSI-based MA", color=color.rgb(120, 206, 255))

// 转换超买超卖水平线数值
OverBought1 = input.int(80, minval=1) * 1.5 - 50
OverBought2 = input.int(90, minval=1) * 1.5 - 50
OverSold1 = input.int(20, minval=1) * 1.5 - 50
OverSold2 = input.int(10, minval=1) * 1.5 - 50

// 绘制转换后的水平线
OB1 = hline(OverBought1 , color=color.red, linestyle=hline.style_dashed)
OB2 = hline(OverBought2 , color=color.red, linestyle=hline.style_dashed)
OS1 = hline(OverSold1 , color=color.green, linestyle=hline.style_dashed)
OS2 = hline(OverSold2 , color=color.green, linestyle=hline.style_dashed)

// 填充转换后的区域
fill(OB1 , OB2, color=color.rgb(255, 82, 82, 80), title="Red Zone Fill")
fill(OS1 , OS2 , color=color.rgb(76, 175, 79, 80), title="Green Zone Fill")

说明 #

• 原始RSI的波动比例完全保留，只是显示尺度被拉伸，不会影响指标的判断逻辑
• 颜色判断依然基于原始RSI值（70/30阈值），确保交易信号逻辑不变
• 所有配套元素（均线、水平线、填充）都同步转换，视觉上完全适配新的显示范围

内容的提问来源于stack exchange，提问作者Colin0686