From b53df53ac864cf26507b4c7e49949b89f691447a Mon Sep 17 00:00:00 2001
From: Suraj Yerramilli
Date: Thu, 4 Jun 2015 00:12:46 +0530
Subject: Corrected the etfe function

---
 R/idframe.R  |  2 +-
 R/nonparam.R | 11 +++++------
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/R/idframe.R b/R/idframe.R
index 31b0b41..be4f0f2 100644
--- a/R/idframe.R
+++ b/R/idframe.R
@@ -176,7 +176,7 @@ plot.idfrd <- function(object){
   require(ggplot2);require(reshape2);require(signal)
 
   mag <- 20*log10(Mod(object$resp))
-  phase <- -180/pi*unwrap(Arg(object$resp))
+  phase <- -360/2/pi*unwrap(Arg(object$resp))
   sys_df <- data.frame(Frequency = object$freq,Gain = mag,Phase = phase)
   melted_sys_df <- melt(sys_df, id.var = c("Frequency"))
   
diff --git a/R/nonparam.R b/R/nonparam.R
index 892027b..d7a6162 100644
--- a/R/nonparam.R
+++ b/R/nonparam.R
@@ -87,7 +87,6 @@ step <- function(model){
   abline(h=0)
 }
 
-#'
 #' Estimate frequency response 
 #' 
 #' Estimates Frequency Response with fixed frequency resolution using 
@@ -112,12 +111,12 @@ spa <- function(data,npad=255){
 #' 
 #' @export
 etfe <- function(data){
-  require(sapa)
   temp <- cbind(as.ts(data$output),as.ts(data$input))
   tempfft <- mvfft(temp)/dim(temp)[1]
-  freq <- seq(from=1,to=dim(temp)[1],by=1)/dim(temp)[1]*pi/data$Ts
-  
-  out <- idfrd(response=as.complex(tempfft[,1]/tempfft[,2]),freq=freq,
+  freq <- seq(from=1,to=ceiling(dim(tempfft)[1]/2),
+              by=1)/ceiling(dim(tempfft)[1]/2)*pi/data$Ts
+  resp <- as.complex(tempfft[,1]/tempfft[,2])
+  out <- idfrd(response=resp[1:ceiling(length(resp)/2)],freq=freq,
                Ts=data$Ts)
   return(out)
-}
+}
\ No newline at end of file
-- 
cgit