# ATR

##### True Range / Average True Range

True range (TR) is a measure of volatility of a High-Low-Close series; average true range (ATR) is a Welles Wilder's style moving average of the TR. Developed by J. Welles Wilder in 1978.

- Keywords
- ts

##### Usage

`ATR(HLC, n = 14, maType, ...)`

##### Arguments

- HLC
Object that is coercible to xts or matrix and contains High-Low-Close prices.

- n
Number of periods for moving average.

- maType
A function or a string naming the function to be called.

- …
Other arguments to be passed to the

`maType`

function.

##### Details

TR incorporates yesterday's close in the calculation (high minus low). E.g. if yesterday's close was higher than today's high, then the TR would equal yesterday's close minus today's low.

The ATR is a component of the Welles Wilder Directional Movement Index
(`DX`

, `ADX`

).

##### Value

A object of the same class as `HLC`

or a matrix (if
`try.xts`

fails) containing the columns:

- tr
The true range of the series.

- atr
The average (as specified by

`ma`

) true range of the series.- trueHigh
The true high of the series.

- trueLow
The true low of the series.

##### References

The following site(s) were used to code/document this indicator: http://www.fmlabs.com/reference/TR.htm http://www.fmlabs.com/reference/ATR.htm http://www.equis.com/Customer/Resources/TAAZ/?c=3&p=35 http://www.linnsoft.com/tour/techind/trueRange.htm http://stockcharts.com/education/IndicatorAnalysis/indic_ATR.html

##### See Also

See `EMA`

, `SMA`

, etc. for moving average
options; and note Warning section. See `DX`

, which uses true
range. See `chaikinVolatility`

for another volatility measure.

##### Examples

`library(TTR)`

```
# NOT RUN {
data(ttrc)
atr <- ATR(ttrc[,c("High","Low","Close")], n=14)
# }
```

*Documentation reproduced from package TTR, version 0.23-1, License: GPL-2*