updating sim documentation

2 files changed, 23 insertions, 17 deletions

diff --git a/R/sim.R b/R/sim.R
index f2930b3..35fe386 100644
--- a/R/sim.R
+++ b/R/sim.R
@@ -1,16 +1,19 @@
-#' Simulate dynamic system
+#' Simulate response of dynamic system
 #' 
-#' Simulate the response of a system given the input
+#' Simulate the response of a system to a given input
 #' 
 #' @param model the linear system to simulate
 #' @param input a vector/matrix containing the input
-#' @param innov an optional times series of innovations. If not provided,
-#' innovations are generated using the \code{rnorm} function
-#' @param sigma standard deviation of the innovations (Default= \code{0})
-#' @param seed integer indicating the seed value of the random number generator
+#' @param addNoise logical variable indicating whether to add noise to the 
+#' response model. (Default: \code{FALSE})
+#' @param innov an optional times series of innovations. If not supplied (specified
+#' as \code{NULL}), gaussian white noise is generated, with the variance specified in 
+#' the model (Property: \code{noiseVar})
+#' @param seed integer indicating the seed value of the random number generator.
+#' Useful for reproducibility purposes.
 #' 
 #' @return
-#' a vector containing the output
+#' a vector containing the simulated output
 #' 
 #' @details
 #' The routine is currently built only for SISO systems. Future versions will
@@ -20,7 +23,7 @@
 #' # ARX Model
 #' u <- rnorm(200,sd=1)
 #' model <- idpoly(A=c(1,-1.5,0.7),B=c(0.8,-0.25),ioDelay=1)
-#' y <- sim(model,u,sigma=0.1)
+#' y <- sim(model,u,addNoise=T)
 #' 
 #' @export
 sim <- function(model,input,addNoise = F,innov=NULL,seed=NULL) UseMethod("sim")
diff --git a/man/sim.Rd b/man/sim.Rd
index 8bf35a5..a4dfe97 100644
--- a/man/sim.Rd
+++ b/man/sim.Rd
@@ -2,27 +2,30 @@
 % Please edit documentation in R/sim.R
 \name{sim}
 \alias{sim}
-\title{Simulate dynamic system}
+\title{Simulate response of dynamic system}
 \usage{
-sim(model, input, innov = NULL, sigma = 0, seed = NULL)
+sim(model, input, addNoise = F, innov = NULL, seed = NULL)
 }
 \arguments{
 \item{model}{the linear system to simulate}
 
 \item{input}{a vector/matrix containing the input}
 
-\item{innov}{an optional times series of innovations. If not provided,
-innovations are generated using the \code{rnorm} function}
+\item{addNoise}{logical variable indicating whether to add noise to the 
+response model. (Default: \code{FALSE})}
 
-\item{sigma}{standard deviation of the innovations (Default= \code{0})}
+\item{innov}{an optional times series of innovations. If not supplied (specified
+as \code{NULL}), gaussian white noise is generated, with the variance specified in 
+the model (Property: \code{noiseVar})}
 
-\item{seed}{integer indicating the seed value of the random number generator}
+\item{seed}{integer indicating the seed value of the random number generator.
+Useful for reproducibility purposes.}
 }
 \value{
-a vector containing the output
+a vector containing the simulated output
 }
 \description{
-Simulate the response of a system given the input
+Simulate the response of a system to a given input
 }
 \details{
 The routine is currently built only for SISO systems. Future versions will
@@ -32,7 +35,7 @@ include support for MIMO systems.
 # ARX Model
 u <- rnorm(200,sd=1)
 model <- idpoly(A=c(1,-1.5,0.7),B=c(0.8,-0.25),ioDelay=1)
-y <- sim(model,u,sigma=0.1)
+y <- sim(model,u,addNoise=T)
 
 }