diff --git a/src/libraries/AMPTOOLS_AMPS/PiPiSWaveAMPK.cc b/src/libraries/AMPTOOLS_AMPS/PiPiSWaveAMPK.cc
index 28fa6249e..91b610056 100644
--- a/src/libraries/AMPTOOLS_AMPS/PiPiSWaveAMPK.cc
+++ b/src/libraries/AMPTOOLS_AMPS/PiPiSWaveAMPK.cc
@@ -52,9 +52,9 @@ void PiPiSWaveAMPK::setParametrization()
 
 
 
-/////////////////////// Amplitude Calculation //////////////////////////
+//////////////////Calculate user variables (CPU only)////////////////////
 
-complex <GDouble> PiPiSWaveAMPK::calcAmplitude( GDouble** pKin ) const
+void PiPiSWaveAMPK::calcUserVars( GDouble** pKin, GDouble* userVars ) const
 {
   TLorentzVector pion1_P4, pion2_P4, dipion_P4, temp_P4;
   
@@ -109,17 +109,28 @@ complex <GDouble> PiPiSWaveAMPK::calcAmplitude( GDouble** pKin ) const
   //Now calculate the T_{11} matrix element using the T11 to M11 relation
   T11 = 1./(M11 - imag*rho11); 
 
+  
+  userVars[uv_ampRe] = T11.real();
+  userVars[uv_ampIm] = T11.imag();
+
+  return;
 
-  return T11;
 }
 
 
+/////////////////////// Amplitude Calculation //////////////////////////
+
+complex <GDouble> PiPiSWaveAMPK::calcAmplitude( GDouble** pKin, GDouble* userVars  ) const
+{
+  return complex <GDouble> ( userVars[uv_ampRe], userVars[uv_ampIm] );
+}
 
 
-//This function may be used instead of the separate amplitude ' breakupMomentumComplex' 
-template<typename mType> complex<GDouble> PiPiSWaveAMPK::breakupMom(mType m, GDouble mDec1, GDouble mDec2) const{
-   complex<GDouble> result = PiPiSWaveAMPK::phaseSpaceFac(m, mDec1, mDec2)*m/GDouble(2.);
-   return result;  
+//This function may be used instead of 'breakupMomentumComplex' from breakupMomentum.cc 
+template<typename mType> complex<GDouble> PiPiSWaveAMPK::breakupMom(mType m, GDouble mDec1, GDouble mDec2) const
+{
+  complex<GDouble> sqrtval = std::sqrt((m*m-(mDec1+mDec2)*(mDec1+mDec2))*(m*m-(mDec1-mDec2)*(mDec1-mDec2)));
+  return sqrtval/GDouble(2.)/m;  
 }
 
 
diff --git a/src/libraries/AMPTOOLS_AMPS/PiPiSWaveAMPK.h b/src/libraries/AMPTOOLS_AMPS/PiPiSWaveAMPK.h
index 3a813e276..0b384f926 100644
--- a/src/libraries/AMPTOOLS_AMPS/PiPiSWaveAMPK.h
+++ b/src/libraries/AMPTOOLS_AMPS/PiPiSWaveAMPK.h
@@ -33,11 +33,17 @@ class PiPiSWaveAMPK : public UserAmplitude<PiPiSWaveAMPK>{
       PiPiSWaveAMPK() : UserAmplitude <PiPiSWaveAMPK>() { }
       PiPiSWaveAMPK( const vector<string> &args );
       ~PiPiSWaveAMPK(){}
-
-      string name() const { return "PiPiSWaveAMPK"; }
+      
+      enum UserVars { uv_ampRe = 0, uv_ampIm = 0, kNumUserVars };
+      unsigned int numUserVars() const { return kNumUserVars; }
+      void calcUserVars( GDouble **pKin, GDouble *userVars ) const;  
+      bool needsUserVarsOnly() const { return true; }
+  
+      string name() const { return "PiPiSWaveAMPK"; }   
       void setParametrization(); 
-      complex <GDouble> calcAmplitude( GDouble** pKin ) const;
+      complex <GDouble> calcAmplitude( GDouble **pKin, GDouble *userVars ) const;
 
+  
 #ifdef GPU_ACCELERATION
 
      void launchGPUKernel( dim3 dimGrid, dim3 dimBlock, GPU_AMP_PROTO ) const;
@@ -60,9 +66,7 @@ class PiPiSWaveAMPK : public UserAmplitude<PiPiSWaveAMPK>{
       const GDouble _kaonNeutralMass = 0.5*(ParticleMass(KLong) + ParticleMass(KShort)); //0.49761400;
       const GDouble _kaonMeanMass = 0.5*(_kaonChargedMass + _kaonNeutralMass); //0.5*(0.49367700 + 0.49761400);
 
-
   
-      complex<GDouble> phaseSpaceFac( GDouble m, GDouble mDec1, GDouble mDec2 ) const;
       template<typename mType>
       complex<GDouble> breakupMom( mType m, GDouble mDec1, GDouble mDec2 ) const;
 
diff --git a/src/programs/AmplitudeAnalysis/isops_plotter/isops_plotter.cc b/src/programs/AmplitudeAnalysis/isops_plotter/isops_plotter.cc
index 2edc2b6d3..29ecb4a65 100644
--- a/src/programs/AmplitudeAnalysis/isops_plotter/isops_plotter.cc
+++ b/src/programs/AmplitudeAnalysis/isops_plotter/isops_plotter.cc
@@ -248,7 +248,7 @@ int main( int argc, char* argv[] ){
 		bool singleData =  irefl == reflname.size() && iamp == amphistname.size();
 		bool singleFlatWave = (irefl == 0 && iamp > 0) || (irefl > 0 && iamp == 0);
 		
-		// if (iplot == PlotGenerator::kGenMC) continue; // no acceptance correction
+		if ( iplot == PlotGenerator::kGenMC) continue; // no acceptance correction
 		if ( iplot == PlotGenerator::kData && !singleData ) continue; // only plot data once
 		if ( iplot == PlotGenerator::kBkgnd && !singleData ) continue; // only plot background once
 		if ( iplot == PlotGenerator::kAccMC && singleFlatWave ) continue; // only plot Flat wave once