2 files changed, 6 insertions, 1 deletions
diff --git a/gr-qtgui/lib/waterfalldisplayform.cc b/gr-qtgui/lib/waterfalldisplayform.cc
index 0b296a81ab..480f18d5b1 100644
--- a/gr-qtgui/lib/waterfalldisplayform.cc
+++ b/gr-qtgui/lib/waterfalldisplayform.cc
@@ -127,7 +127,7 @@ WaterfallDisplayForm::newData(const QEvent *updateEvent)
   }
 
   getPlot()->plotNewData(dataPoints, numDataPoints,
-			 d_update_time, dataTimestamp, 0);
+			 _time_per_slice, dataTimestamp, 0);
 }
 
 void
@@ -208,6 +208,9 @@ WaterfallDisplayForm::setFrequencyRange(const double centerfreq,
   double units = pow(10, (units10-fmod(units10, 3.0)));
   int iunit = static_cast<int>(units3);
 
+  _samp_rate = bandwidth;
+  _time_per_slice = (1.0/bandwidth)*_fftsize;
+
   getPlot()->setFrequencyRange(centerfreq, bandwidth,
 			       units, strunits[iunit]);
   getPlot()->replot();
diff --git a/gr-qtgui/lib/waterfalldisplayform.h b/gr-qtgui/lib/waterfalldisplayform.h
index 26f60bdd84..a6add831fd 100644
--- a/gr-qtgui/lib/waterfalldisplayform.h
+++ b/gr-qtgui/lib/waterfalldisplayform.h
@@ -81,6 +81,8 @@ private:
   uint64_t _numRealDataPoints;
   QIntValidator* _intValidator;
 
+  double _samp_rate;
+  double _time_per_slice;
   int _fftsize;
   float _fftavg;
   gr::filter::firdes::win_type _fftwintype;