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Miha Kralj
56 lines
1.9 KiB
Plaintext
56 lines
1.9 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("Psychological Line (PSL)", "PSL", overlay=false)
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//@function Calculates Psychological Line — percentage of up-bars over lookback
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//@param source Series to evaluate (typically close)
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//@param period Lookback period (number of bars to count)
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//@returns PSL value in [0, 100]
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//@description PSL counts the number of bars where source > source[1] (up-bars)
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// within the lookback window and expresses it as a percentage:
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// PSL = 100 × (count of up-bars in period) / period
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// Uses a circular buffer storing 1.0 (up) or 0.0 (down/unchanged) with
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// a running sum for O(1) updates per bar.
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// Readings above 50 indicate bullish sentiment (more up-bars than down).
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// Extreme readings (>75 or <25) suggest overbought/oversold conditions.
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// First bar has no prior close reference — defaults to 0 (not an up-bar).
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psl(series float source, 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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var array<float> buffer = array.new_float(period, na)
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var int head = 0
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var float upSum = 0.0
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var int count = 0
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float prev = source[1]
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float upVal = not na(prev) and source > prev ? 1.0 : 0.0
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float oldest = array.get(buffer, head)
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if not na(oldest)
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upSum -= oldest
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else
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count += 1
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upSum += upVal
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array.set(buffer, head, upVal)
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head := (head + 1) % period
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100.0 * upSum / math.max(1, count)
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// ---------- Main loop ----------
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// Inputs
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i_period = input.int(12, "Period", minval=1)
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i_source = input.source(close, "Source")
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// Calculation
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psl_value = psl(i_source, period=i_period)
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// Plot
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plot(psl_value, "PSL", color=color.yellow, linewidth=2)
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hline(50, "Midline", color=color.gray, linestyle=hline.style_dotted)
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hline(75, "Overbought", color=color.red, linestyle=hline.style_dashed)
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hline(25, "Oversold", color=color.green, linestyle=hline.style_dashed)
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