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https://github.com/mihakralj/QuanTAlib.git
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Miha Kralj
80 lines
3.2 KiB
Plaintext
80 lines
3.2 KiB
Plaintext
// Licensed under the Apache License, Version 2.0
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// © mihakralj
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//@version=6
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indicator("RAVI: Chande Range Action Verification Index", "RAVI", overlay=false)
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//@function Calculates Range Action Verification Index using short/long SMA divergence
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//@param shortPeriod Lookback period for fast SMA (default: 7, ~10% of longPeriod)
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//@param longPeriod Lookback period for slow SMA (default: 65, ~13 weeks daily)
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//@returns RAVI value as absolute percentage divergence between short and long SMAs
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//@references Tushar Chande, "Beyond Technical Analysis", Wiley, 2nd ed. (2001), pp. 66-70
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//@optimized O(1) per bar via circular buffer running sums for both SMAs
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ravi(simple int shortPeriod, simple int longPeriod) =>
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if shortPeriod <= 0
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runtime.error("Short period must be greater than 0")
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if longPeriod <= 0
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runtime.error("Long period must be greater than 0")
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if shortPeriod >= longPeriod
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runtime.error("Short period must be less than long period")
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// Circular buffer for short SMA (O(1) running sum)
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var array<float> shortBuf = array.new_float(shortPeriod, na)
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var int shortHead = 0
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var int shortFilled = 0
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var float shortSum = 0.0
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// Circular buffer for long SMA (O(1) running sum)
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var array<float> longBuf = array.new_float(longPeriod, na)
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var int longHead = 0
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var int longFilled = 0
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var float longSum = 0.0
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// Update short SMA buffer
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float oldShort = array.get(shortBuf, shortHead)
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if not na(oldShort)
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shortSum -= oldShort
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shortSum += close
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array.set(shortBuf, shortHead, close)
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shortFilled := math.min(shortFilled + 1, shortPeriod)
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shortHead := (shortHead + 1) % shortPeriod
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// Update long SMA buffer
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float oldLong = array.get(longBuf, longHead)
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if not na(oldLong)
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longSum -= oldLong
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longSum += close
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array.set(longBuf, longHead, close)
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longFilled := math.min(longFilled + 1, longPeriod)
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longHead := (longHead + 1) % longPeriod
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float result = na
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if shortFilled >= shortPeriod and longFilled >= longPeriod
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// Step 1: Compute short-period SMA
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float smaShort = shortSum / shortPeriod
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// Step 2: Compute long-period SMA
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float smaLong = longSum / longPeriod
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// Step 3: RAVI = |SMA(short) - SMA(long)| / SMA(long) * 100
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// Guard against division by zero (long SMA at zero)
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if math.abs(smaLong) > 1e-10
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result := math.abs(smaShort - smaLong) / math.abs(smaLong) * 100.0
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result
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// ---------- Main loop ----------
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// Inputs
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i_short = input.int(7, "Short Period", minval=1, maxval=100, tooltip="Fast SMA period (~10% of long period; Chande default: 7)")
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i_long = input.int(65, "Long Period", minval=2, maxval=500, tooltip="Slow SMA period (~13 weeks daily; Chande default: 65)")
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i_threshold = input.float(3.0, "Threshold", minval=0.0, maxval=20.0, step=0.5, tooltip="Trend/range classification level (Chande default: 3%)")
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// Calculation
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ravi_value = ravi(i_short, i_long)
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// Plot
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plot(ravi_value, "RAVI", color=color.yellow, linewidth=2)
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hline(i_threshold, "Threshold", color=color.new(color.red, 50), linestyle=hline.style_dashed)
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hline(0, "Zero Line", color=color.new(color.gray, 70), linestyle=hline.style_dotted)
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