1 files changed, 28 insertions, 0 deletions
diff --git a/R/estpoly.R b/R/estpoly.R
index 6e04e0d..96c258e 100644
--- a/R/estpoly.R
+++ b/R/estpoly.R
@@ -21,6 +21,34 @@ plot.estPoly <- function(model,newdata=NULL){
 
 #' Estimate ARX Models
 #' 
+#' Fit an ARX model of the specified order given the input-output data 
+#' 
+#' @param data an object of class \code{idframe}
+#' @param order: Specification of the orders: the three integer components 
+#' (na,nb,nk) are the order of polynolnomial A, order of polynomial B and 
+#' the input-output delay
+#' 
+#' @details
+#' ARX models are of the form \\
+#' 
+#' @return
+#' An object having classes \code{estARX} and \code{estPoly} containing 
+#' the following elements:
+#' 
+#' 
+#' @references
+#' Arun K. Tangirala (2015), Principles of System Identification: Theory and 
+#' Practice, CRC Press, Boca Raton. Section 21.6.1
+#' 
+#' Lennart Ljung (1999) System Identification: Theory for the User, 
+#' 2nd Edition, Prentice Hall, New York. Section 10.1
+#' 
+#' @examples
+#' data(arxsim)
+#' model <- estARX(data,c(2,1,1))
+#' summary(model) # obtain estimates and their covariances
+#' plot(model) # plot the predicted and actual responses
+#' 
 #' @export
 estARX <- function(data,order=c(0,1,0)){
   y <- as.matrix(data$output)