Keltner Channels Wikipedia.
- middle = EMA(close, period)
- upper = middle + mult * ATR(period)
- lower = middle - mult * ATR(period)
The EMA and ATR are both seeded at index period - 1, so the channels
are defined for the same points. Bars are maps with at least :high,
:low and :close. See TAlib for the remaining conventions:
chronological order, oldest first, nil when there is not enough data.
Summary
Functions
Calculate the latest Keltner Channels as a map.
Calculate the full Keltner Channels series.
Functions
@spec keltner([map()], pos_integer(), number()) :: %{upper: float(), middle: float(), lower: float()} | nil
Calculate the latest Keltner Channels as a map.
Parameters
- bars: list of bars, oldest first.
- period: EMA/ATR lookback window, a positive integer (default 20).
- mult: ATR multiplier, a number (default 2).
Examples
iex> bars = [
...> %{high: 12, low: 8, close: 10},
...> %{high: 11, low: 9, close: 10},
...> %{high: 13, low: 9, close: 12}
...> ]
iex> %{upper: u, middle: m, lower: l} = TAlib.Indicators.Keltner.keltner(bars, 2, 2)
iex> {Float.round(u, 4), Float.round(m, 4), Float.round(l, 4)}
{17.3333, 11.3333, 5.3333}@spec keltner_list([map()], pos_integer(), number()) :: [map() | nil]
Calculate the full Keltner Channels series.
Returns a list aligned with bars: the first period - 1 entries are
nil, and every later entry is a map with :upper, :middle and
:lower.
Parameters
- bars: list of bars, oldest first.
- period: EMA/ATR lookback window, a positive integer (default 20).
- mult: ATR multiplier, a number (default 2).
Examples
iex> bars = [
...> %{high: 12, low: 8, close: 10},
...> %{high: 11, low: 9, close: 10},
...> %{high: 13, low: 9, close: 12}
...> ]
iex> TAlib.Indicators.Keltner.keltner_list(bars, 2) |> Enum.count(&is_nil/1)
2