# ROC with Bands

Rate of Change (ROC) with Bands, created by Vitali Apirine, is a volatility banded variant of Rate of Change (ROC). [Discuss]

```
// usage
IEnumerable<RocWbResult> results =
quotes.GetRocWb(lookbackPeriods, emaPeriods, stdDevPeriods);
```

## Parameters

`lookbackPeriods`

* int* - Number of periods (

`N`

) to go back. Must be greater than 0. Typical values range from 10-20.`emaPeriods`

* int* - Number of periods for the ROC EMA line. Must be greater than 0. Standard is 3.

`stdDevPeriods`

* int* - Number of periods the standard deviation for upper/lower band lines. Must be greater than 0 and not more than

`lookbackPeriods`

. Standard is to use same value as `lookbackPeriods`

.### Historical quotes requirements

You must have at least `N+1`

periods of `quotes`

to cover the warmup periods.

`quotes`

is a collection of generic `TQuote`

historical price quotes. It should have a consistent frequency (day, hour, minute, etc). See the Guide for more information.

## Response

```
IEnumerable<RocWbResult>
```

- This method returns a time series of all available indicator values for the
`quotes`

provided. - It always returns the same number of elements as there are in the historical quotes.
- It does not return a single incremental indicator value.
- The first
`N`

periods will have`null`

values for ROC since there’s not enough data to calculate.

### RocWbResult

`Date`

* DateTime* - Date from evaluated

`TQuote`

`Roc`

* double* - Rate of Change over

`N`

lookback periods (%, not decimal)`RocEma`

* double* - Exponential moving average (EMA) of

`Roc`

`UpperBand`

* double* - Upper band of ROC (overbought indicator)

`LowerBand`

* double* - Lower band of ROC (oversold indicator)

### Utilities

See Utilities and helpers for more information.

## Chaining

This indicator may be generated from any chain-enabled indicator or method.

```
// example
var results = quotes
.Use(CandlePart.HL2)
.GetRocWb(..);
```

Results can be further processed on `Roc`

with additional chain-enabled indicators.

```
// example
var results = quotes
.GetRocWb(..)
.GetEma(..);
```