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QuanTAlib/lib/errors/logcosh/logcosh.pine
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// Licensed under the Apache License, Version 2.0
// © mihakralj
//@version=6
indicator("Log-Cosh Loss", "LogCosh", overlay=false)
//@function Computes log(cosh(x)) in a numerically stable way
//@param x The input value
//@returns log(cosh(x))
stable_logcosh(float x) =>
float LOG2 = 0.6931471805599453
float absX = math.abs(x)
// For large values, use asymptotic approximation to avoid overflow
absX > 20.0 ? absX - LOG2 : math.log((math.exp(x) + math.exp(-x)) / 2.0)
//@function Calculates Log-Cosh Loss
//@param actual Series of actual values
//@param predicted Series of predicted/forecast values
//@param length Rolling window for averaging
//@returns Mean log-cosh loss over the window
logcosh_loss(series float actual, series float predicted, simple int length) =>
// Compute log-cosh loss for current bar
float error = nz(actual, 0.0) - nz(predicted, 0.0)
float loss = stable_logcosh(error)
// Rolling mean of losses
float result = ta.sma(loss, length)
result
// ---------- Main loop ----------
// Inputs
i_length = input.int(14, "Length", minval=1)
i_actual = input.source(close, "Actual")
i_predicted = input.source(open, "Predicted")
// Calculation
logcosh_value = logcosh_loss(i_actual, i_predicted, i_length)
// Plot
plot(logcosh_value, "Log-Cosh Loss", color=color.yellow, linewidth=2)
hline(0, "Zero", color=color.gray, linestyle=hline.style_dotted)