# tripleExponentialDerivative() function

`tripleExponentialDerivative()` returns the triple exponential derivative (TRIX) values using `n` points.

Triple exponential derivative, commonly referred to as “TRIX,” is a momentum indicator and oscillator. A triple exponential derivative uses the natural logarithm (log) of input data to calculate a triple exponential moving average over the period of time. The calculation prevents cycles shorter than the defined period from being considered by the indicator. `tripleExponentialDerivative()` uses the time between `n` points to define the period.

Triple exponential derivative oscillates around a zero line. A positive momentum oscillator value indicates an overbought market; a negative value indicates an oversold market. A positive momentum indicator value indicates increasing momentum; a negative value indicates decreasing momentum.

#### Triple exponential moving average rules

• A triple exponential derivative is defined as:
• `TRIX[i] = ((EMA3[i] / EMA3[i - 1]) - 1) * 100`
• `EMA3 = EMA(EMA(EMA(data)))`
• If there are not enough values to calculate a triple exponential derivative, the output `_value` is `NaN`; all other columns are the same as the last record of the input table.
• The function behaves the same way as the `exponentialMovingAverage()` function:
• The function ignores `null` values.
• The function operates only on the `_value` column.
##### Function type signature
``````(<-tables: stream[{A with _value: B}], n: int) => stream[{A with _value: float}] where A: Record, B: Numeric
``````

## Parameters

### n

(Required) Number of points to use in the calculation.

### tables

Input data. Default is piped-forward data (`<-`).

## Examples

### Calculate a two-point triple exponential derivative

``````import "sampledata"

sampledata.float()
|> tripleExponentialDerivative(n: 2)
``````