man/bollingerBands.Rd

% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/bollingerBands.R
\name{BBands}
\alias{BBands}
\alias{bollingerBands}
\title{Bollinger Bands}
\usage{
BBands(HLC, n = 20, maType, sd = 2, ...)
}
\arguments{
\item{HLC}{Object that is coercible to xts or matrix and contains
High-Low-Close prices.  If only a univariate series is given, it will be
used.  See details.}

\item{n}{Number of periods for moving average.}

\item{maType}{A function or a string naming the function to be called.}

\item{sd}{The number of standard deviations to use.}

\item{\dots}{Other arguments to be passed to the \code{maType} function.}
}
\value{
A object of the same class as \code{HLC} or a matrix (if
\code{try.xts} fails) containing the columns:
\describe{
 \item{ dn }{ The lower Bollinger Band. }
 \item{ mavg }{ The middle Moving Average (see notes). }
 \item{ up }{ The upper Bollinger Band. }
 \item{ pctB }{ The \%B calculation. }
}
}
\description{
Bollinger Bands are a way to compare a security's volatility and price levels
over a period of time.  Developed by John Bollinger.
}
\details{
Bollinger Bands consist of three lines:

The middle band is generally a 20-period SMA of the typical price ([high +
low + close]/3).  The upper and lower bands are \code{sd} standard deviations
(generally 2) above and below the MA.

The middle band is usually calculated using the typical price, but if a
univariate series (e.g. Close, Weighted Close, Median Price, etc.) is
provided, it will be used instead.
}
\note{
Using any moving average other than SMA will result in inconsistencies
between the moving average calculation and the standard deviation
calculation.  Since, by definition, a rolling standard deviation uses a
simple moving average.
}
\examples{

## The examples below show the differences between using a
## High-Low-Close series, and just a close series when
## calculating Bollinger Bands.
data(ttrc)
bbands.HLC <- BBands( ttrc[,c("High","Low","Close")] )
bbands.close <- BBands( ttrc[,"Close"] )
}
\references{
The following site(s) were used to code/document this
indicator:\cr \url{http://www.fmlabs.com/reference/Bollinger.htm}\cr
\url{http://www.fmlabs.com/reference/BollingerWidth.htm}\cr
\url{https://www.metastock.com/Customer/Resources/TAAZ/?p=36}\cr
\url{https://www.linnsoft.com/techind/bollinger-bands}\cr
\url{http://www.stockcharts.com/school/doku.php?id=chart_school:technical_indicators:bollinger_bands}\cr
\url{http://www.stockcharts.com/school/doku.php?id=chart_school:technical_indicators:bollinger_band_width}\cr
}
\seealso{
See \code{\link{EMA}}, \code{\link{SMA}}, etc. for moving average
options; and note Warning section.
}
\author{
Joshua Ulrich
}
\keyword{ts}