// The MIT License (MIT)
// © mihakralj
//@version=6
indicator("Cumulative Mean (CUMMEAN)", "CUMMEAN", overlay=false, precision=8)

//@function Calculates the cumulative arithmetic mean (average) of a series from the start of the data.
//@doc https://github.com/mihakralj/pinescript/blob/main/indicators/statistics/cummean.md
//@param src series float Input data series.
//@returns series float The cumulative mean of the series, or na if all data so far is na.
cummean(series float src) =>
    var float cumulative_sum = 0.0
    var int valid_data_count = 0
    if not na(src)
        cumulative_sum += src
        valid_data_count += 1
    valid_data_count > 0 ? cumulative_sum / valid_data_count : na

// ---------- Main loop ----------

// Inputs
i_source = input.source(close, "Source")

// Calculation
cummean_value = cummean(i_source)

// Plot
plot(cummean_value, "CumMean", color=color.new(color.blue, 0, color=color.yellow, linewidth=2), linewidth=2)