\name{Waveforms}
\encoding{latin1}
\alias{Waveforms}
\alias{sine}
\alias{sawtooth}
\alias{square}
\alias{silence}
\alias{noise}
\alias{pulse}
\title{Create Wave Objects of Special Waveforms}
\description{Create a \code{\link{Wave}} object of special waveform such as
silcence, power law (white, red, pink, ...) noise, sawtooth, sine, square, and pulse.}
\usage{
noise(kind = c("white", "pink", "power", "red"), duration = samp.rate, 
      samp.rate = 44100, bit = 1, stereo = FALSE, 
      xunit = c("samples", "time"), alpha = 1, ...)

pulse(freq, duration = samp.rate, from = 0, samp.rate = 44100,
      bit = 1, stereo = FALSE, xunit = c("samples", "time"),
      width = 0.1, plateau = 0.2, interval = 0.5, ...)

sawtooth(freq, duration = samp.rate, from = 0, samp.rate = 44100, 
         bit = 1, stereo = FALSE, xunit = c("samples", "time"), 
         reverse = FALSE, ...)

silence(duration = samp.rate, from = 0, samp.rate = 44100, 
        bit = 1, stereo = FALSE, xunit = c("samples", "time"), ...)

sine(freq, duration = samp.rate, from = 0, samp.rate = 44100, 
     bit = 1, stereo = FALSE, xunit = c("samples", "time"), ...)

square(freq, duration = samp.rate, from = 0, samp.rate = 44100, 
       bit = 1, stereo = FALSE, xunit = c("samples", "time"), 
       up = 0.5, ...)
}
\arguments{
  \item{kind}{The kind of noise, \dQuote{white}, \dQuote{pink}, \dQuote{power}, or \dQuote{red}
    (these are not dB adjusted (!) but all except for \dQuote{white} are linear decreasing on a log-log scale).
    Algorithm for generating power law noise is taken from Timmer and \enc{König}{Koenig} (1995).}
  \item{freq}{The frequency (in Hertz) to be generated.}
  \item{duration}{Duration of the \code{Wave} in \code{xunit}.}
  \item{from}{Starting value of the \code{Wave} in \code{xunit}.}
  \item{samp.rate}{Sampling rate of the \code{Wave}.}
  \item{bit}{Resolution of the \code{Wave} and rescaling unit. This may be\cr
        \code{1} (default) for rescaling to numeric values in [-1,1],\cr
        \code{8} (i.e. 8-bit) for rescaling to integers in [0, 254],\cr
        \code{16} (i.e. 16-bit) for rescaling to integers in [-32767, 32767],\cr
        \code{24} (i.e. 24-bit) for rescaling to integers in [-8388607, 8388607],\cr
        \code{32} (i.e. 32-bit) for rescaling either to integers in [-2147483647, 2147483647] 
                    (PCM Wave format if \code{pcm = TRUE}) or to numeric values in [-1, 1] 
                    (FLOAT_IEEE Wave format if \code{pcm = FALSE}),\cr
        \code{64} (i.e. 64-bit) for rescaling to numeric values in [-1, 1] (FLOAT_IEEE Wave format), and\cr
        \code{0} for not rescaling at all. These numbers are internally passed to \code{\link{normalize}}.
        
        The \code{Wave} slot \code{bit} will be set to 32 if \code{bit = 0}, \code{bit = 1} or \code{bit = 32}.}  
  \item{stereo}{Logical, if \code{TRUE}, a stereo sample will be generated.
    The right channel is identical to the left one for \code{sawtooth}, \code{silence},
    \code{sine}, and \code{square}. For \code{noise}, both channel are independent.}
  \item{xunit}{Character indicating which units are used
    (both in arguments \code{duration} and \code{from}).
    If \code{xunit = "time"}, the unit is time in seconds, otherwise the number of samples.}
  \item{alpha}{The power for the power law noise (defaults are 1 for pink and 1.5 for red noise)
    \eqn{1/f^{\alpha}}{(1/f)^alpha}.}
  \item{reverse}{Logical, if \code{TRUE}, the waveform will be mirrored vertically.}
  \item{up}{A number between 0 and 1 giving the percentage of the waveform at max value 
    (= 1 - percentage of min value).}
  \item{width}{Relative pulses width: the proportion of time the amplitude is non-zero.}
  \item{plateau}{Relative plateau width: the proportion of the pulse width where amplitude is \enc{±}{+/-}1.}
  \item{interval}{Relative interval between the up-going and down-going pulses with respect to the center of the wave
    period (0: immediatly after up-going, 1: center of the wave period).}
  \item{...}{Further arguments to be passed to \code{\link{Wave}} through the internal function \code{postWaveform}.}
}
\value{
  A \code{\link{Wave}} object.
}
\references{
J. Timmer and M. \enc{König}{Koenig} (1995): On generating power law noise. Astron. Astrophys. 300, 707-710.
}
\author{Uwe Ligges \email{ligges@statistik.tu-dortmund.de},
    partly based on code from Matthias Heymann's former package \sQuote{sound},
    Anita Thieler, Guillaume \enc{Guénard}{Guenard}}
\seealso{\link{Wave-class}, \code{\link{Wave}}, \code{\link{normalize}}, \code{\link{noSilence}}}
\examples{
Wobj <- sine(440, duration = 1000)
Wobj2 <- noise(duration = 1000)
Wobj3 <- pulse(220, duration = 1000)
plot(Wobj)
plot(Wobj2)
plot(Wobj3)
}
\keyword{datagen}
\concept{Wave}
\concept{sound}
\concept{waveform}
\concept{silcence}
\concept{sample}