Matching TradingView’s numbers

People moving from TradingView check one thing first: do the numbers match? Libraries often disagree on RSI, ATR and long EMAs, mostly in how the first values are started (seeded) and how much warm-up history there is. LumiBot’s built-ins follow the published Pine Script v6 formulas:

Indicator	How LumiBot computes it (Pine v6 rule)
ema	Starts with the simple average of the first length values, then alpha = 2 / (length + 1).
rsi	Gains and losses smoothed with Wilder’s average (rma, alpha = 1 / length), seeded with a simple average.
atr	True range smoothed with rma.
bbands	Population standard deviation (divide by length, not length - 1).
stoch	Not clamped to 0..100 (same as Pine).
vwap	Restarts at each UTC day.

The test suite checks every built-in against plain-loop reference implementations written from those formulas, on top of hand-worked values.

Why your numbers may still differ

• Warm-up. EMA and RSI depend on every bar since the start. TradingView starts at the first bar it loaded; if you load fewer bars, early values differ. Load several times length bars and compare recent values.

• Different data. Exchanges and data vendors disagree slightly on candles, especially volume. Compare against the same exchange.

• Session vs UTC. LumiBot’s vwap resets at UTC midnight. A stock chart that resets at the session open will differ.

• The live bar. TradingView redraws the live bar on every tick. Compare closed bars.

How to check a value yourself

1. On TradingView, add the indicator to a chart and note its value on a few closed bars (or export the chart data, where your plan allows it).

2. Load the same exchange’s candles into a DataFrame (for crypto, Stream an indicator live from a crypto exchange shows how).

3. Run registry.create("rsi", length=14).compute(df) and compare the same bars.

Porting your own Pine script

Map each Pine piece to Python. All of these live in lumibot.indicators.primitives and cost the same small time per bar:

Pine	LumiBot
ta.sma	RollingSMA
ta.ema	SeededEMA
ta.rma	SeededRMA
ta.stdev	RollingStdev
ta.highest / ta.lowest	RollingMax / RollingMin
var variables	keys in state

Only port code you wrote yourself or have the right to use.