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// Licensed under the Apache License, Version 2.0
// © mihakralj
//@version=6
indicator("Weighted Average (WAVG)", "WAVG", overlay=true)
//@function Calculates rolling linearly-weighted average over a lookback window
//@param source Series to evaluate (typically close)
//@param period Lookback period (number of bars)
//@returns Weighted average where weight[i] = position from oldest (1) to newest (period)
//@description WAVG assigns linearly increasing weights to the lookback window:
// weight_i = i + 1 for i = 0 (oldest) to period-1 (newest)
// WAVG = Σ(weight_i × value_i) / Σ(weight_i)
// Σ(weight_i) = period × (period + 1) / 2
// Uses a circular buffer for O(1) updates per bar. On each new bar:
// 1. Subtract the departing oldest value's contribution from weightedSum
// 2. Shift all existing weights down by 1 (subtract runningSum from weightedSum)
// 3. Add the new value with weight = count (current fill level)
// runningSum tracks the unweighted sum for the shift operation.
// §3 count-based warmup: during filling, actual count < period, and
// denominator = count × (count + 1) / 2.
// This is mathematically identical to WMA but categorized as a statistical measure.
wavg(series float source, simple int period) =>
if period <= 0
runtime.error("Period must be greater than 0")
var array<float> buffer = array.new_float(period, na)
var int head = 0
var float weightedSum = 0.0
var float runningSum = 0.0
var int count = 0
float srcVal = nz(source)
float oldest = array.get(buffer, head)
if not na(oldest)
runningSum -= oldest
else
count += 1
weightedSum -= runningSum
runningSum += srcVal
weightedSum += float(count) * srcVal
array.set(buffer, head, srcVal)
head := (head + 1) % period
float denom = float(count) * float(count + 1) / 2.0
denom > 0.0 ? weightedSum / denom : srcVal
// ---------- Main loop ----------
// Inputs
i_source = input.source(close, "Source")
i_period = input.int(14, "Period", minval=1)
// Calculation
wavg_value = wavg(i_source, i_period)
// Plot
plot(wavg_value, "WAVG", color=color.yellow, linewidth=2)