From 1c5069bc489b50c5d3af446cbc81ad3bfcec9590 Mon Sep 17 00:00:00 2001
From: Andreas Suter <andreas.suter@psi.ch>
Date: Thu, 11 Apr 2019 16:46:13 +0200
Subject: [PATCH] fix of wrong offset in time domain data before Fourier.

---
 src/classes/PFourier.cpp | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/classes/PFourier.cpp b/src/classes/PFourier.cpp
index 4c088017..f644e20d 100644
--- a/src/classes/PFourier.cpp
+++ b/src/classes/PFourier.cpp
@@ -893,29 +893,29 @@ void PFourier::PrepareFFTwInputData(UInt_t apodizationTag)
 
   Double_t mean = 0.0;
   if (fDCCorrected) {
-    for (UInt_t i=start; i<fNoOfData; i++) {
+    for (UInt_t i=start; i<start+fNoOfData; i++) {
       mean += fData->GetBinContent(i);
     }
-    mean /= (Double_t)(fNoOfData-start);
+    mean /= (Double_t)fNoOfData;
   }  
 
   // 2nd fill fIn
   if (fUseFFTW) {
-    for (UInt_t i=0; i<fNoOfData-start; i++) {
+    for (UInt_t i=0; i<fNoOfData; i++) {
       fIn[i][0] = fData->GetBinContent(i+start) - mean;
       fIn[i][1] = 0.0;
     }
-    for (UInt_t i=fNoOfData-start; i<fNoOfBins; i++) {
+    for (UInt_t i=fNoOfData; i<fNoOfBins; i++) {
       fIn[i][0] = 0.0;
       fIn[i][1] = 0.0;
     }
   } else {
-    for (UInt_t i=0; i<fNoOfData-start; i++) {
+    for (UInt_t i=0; i<fNoOfData; i++) {
 #ifdef HAVE_DKS
       fInDKS[i] = fData->GetBinContent(i+start) - mean;
 #endif
     }
-    for (UInt_t i=fNoOfData-start; i<fNoOfBins; i++) {
+    for (UInt_t i=fNoOfData; i<fNoOfBins; i++) {
 #ifdef HAVE_DKS
       fInDKS[i] = 0.0;
 #endif