Documenting spa

2 files changed, 41 insertions, 2 deletions

diff --git a/R/nonparam.R b/R/nonparam.R
index 73c76f7..e4d0b07 100644
--- a/R/nonparam.R
+++ b/R/nonparam.R
@@ -114,7 +114,26 @@ step <- function(model){
 #' @param npad an integer representing the total length of each time series 
 #' to analyze after padding with zeros. This argument allows the user to 
 #' control the spectral resolution of the SDF estimates: the normalized 
-#' frequency interval is deltaf=1/npad. (Default:)
+#' frequency interval is deltaf=1/npad. (Default: 255)
+#' 
+#' @details
+#' The function calls the \code{SDF} function in the \code{sapa} package to
+#' compute the cross-spectral densities. The method used is \strong{Welch's 
+#' Overlapped Segment Averaging} with a normalized \strong{Hanning} window.
+#' The overlap used is 50%. 
+#' 
+#' @return
+#' an \code{idfrd} object containing the estimated frequency response
+#' 
+#' @references
+#' Arun K. Tangirala (2015), \emph{Principles of System Identification: 
+#' Theory and Practice}, CRC Press, Boca Raton. Sections 16.5 and 20.4
+#' 
+#' @seealso \code{\link[sapa]{SDF}}
+#' 
+#' @examples
+#' data(frf)
+#' frf <- spa(data)
 #' 
 #' @export
 spa <- function(data,npad=255){
diff --git a/man/spa.Rd b/man/spa.Rd
index 96fcb02..13778ea 100644
--- a/man/spa.Rd
+++ b/man/spa.Rd
@@ -12,10 +12,30 @@ spa(data, npad = 255)
 \item{npad}{an integer representing the total length of each time series
 to analyze after padding with zeros. This argument allows the user to
 control the spectral resolution of the SDF estimates: the normalized
-frequency interval is deltaf=1/npad. (Default:)}
+frequency interval is deltaf=1/npad. (Default: 255)}
+}
+\value{
+an \code{idfrd} object containing the estimated frequency response
 }
 \description{
 Estimates Frequency Response with fixed frequency resolution using
 spectral analysis
 }
+\details{
+The function calls the \code{SDF} function in the \code{sapa} package to
+compute the cross-spectral densities. The method used is \strong{Welch's
+Overlapped Segment Averaging} with a normalized \strong{Hanning} window.
+The overlap used is 50%.
+}
+\examples{
+data(frf)
+frf <- spa(data)
+}
+\references{
+Arun K. Tangirala (2015), \emph{Principles of System Identification:
+Theory and Practice}, CRC Press, Boca Raton. Sections 16.5 and 20.4
+}
+\seealso{
+\code{\link[sapa]{SDF}}
+}