mirror of
https://github.com/mihakralj/QuanTAlib.git
synced 2026-07-27 17:27:43 +00:00
Miha Kralj
57 lines
1.7 KiB
Plaintext
57 lines
1.7 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("DeMarker Oscillator (DEM)", "DEM", overlay=false)
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//@function Calculates DEM (DeMarker Oscillator)
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//@param period SMA lookback period (default 14)
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//@returns DEM value in [0, 1] range; 0.3=oversold, 0.7=overbought
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//@optimized Uses 2 circular buffers for O(1) per-bar SMA computation
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dem(simple int period) =>
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if period <= 0
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runtime.error("Period must be greater than 0")
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if period > 5000
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runtime.error("Period exceeds maximum of 5000")
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float prevHigh = nz(high[1], high)
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float prevLow = nz(low[1], low)
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float deMax = math.max(high - prevHigh, 0.0)
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float deMin = math.max(prevLow - low, 0.0)
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var array<float> deMaxBuf = array.new_float(period, 0.0)
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var array<float> deMinBuf = array.new_float(period, 0.0)
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var int idx = 0
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var float deMaxSum = 0.0
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var float deMinSum = 0.0
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deMaxSum -= array.get(deMaxBuf, idx)
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deMinSum -= array.get(deMinBuf, idx)
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array.set(deMaxBuf, idx, deMax)
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array.set(deMinBuf, idx, deMin)
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deMaxSum += deMax
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deMinSum += deMin
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idx := (idx + 1) % period
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float denom = deMaxSum + deMinSum
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float result = denom != 0.0 ? deMaxSum / denom : 0.5
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result
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// ---------- Main loop ----------
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// Inputs
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i_period = input.int(14, "Period", minval=1, maxval=5000, tooltip="SMA smoothing period (traditional: 14)")
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// Calculation
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dem_value = dem(i_period)
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// Plot
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plot(dem_value, "DEM", color.new(color.yellow, 0), 2)
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hline(0.7, "Overbought", color=color.red, linestyle=hline.style_dotted)
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hline(0.5, "Midline", color=color.gray, linestyle=hline.style_dotted)
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hline(0.3, "Oversold", color=color.green, linestyle=hline.style_dotted)
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