diff --git a/lib/Core/Plot.cpp b/lib/Core/Plot.cpp
index 3a236cd..a696be6 100644
--- a/lib/Core/Plot.cpp
+++ b/lib/Core/Plot.cpp
@@ -184,7 +184,7 @@ PlotData::PlotData(const DMatSample &x, const DVec &y, const bool abs)
     }
     else
     {
-        setCommand("'" + tmpFileName + "' u 1:($3):2 w xerr");
+        setCommand("'" + tmpFileName + "' u 1:(abs($3)):2 w xerr");
     }
 }
 
@@ -206,6 +206,60 @@ PlotData::PlotData(const XYStatData &data, const Index i, const Index j, const b
     setCommand("'" + tmpFileName + "' " + usingCmd);
 }
 
+// PlotPoint constructor ///////////////////////////////////////////////////////
+PlotPoint::PlotPoint(const double x, const double y)
+{
+    DMat d(1, 2);
+    string usingCmd, tmpFileName;
+
+    d(0, 0)     = x;
+    d(0, 1)     = y;
+    tmpFileName = dumpToTmpFile(d);
+    pushTmpFile(tmpFileName);
+    setCommand("'" + tmpFileName + "' u 1:2");
+}
+
+PlotPoint::PlotPoint(const DSample &x, const double y)
+{
+    DMat d(1, 3);
+    string usingCmd, tmpFileName;
+
+    d(0, 0)     = x[central];
+    d(0, 2)     = y;
+    d(0, 1)     = sqrt(x.variance());
+    tmpFileName = dumpToTmpFile(d);
+    pushTmpFile(tmpFileName);
+    setCommand("'" + tmpFileName + "' u 1:3:2 w xerr");
+}
+
+PlotPoint::PlotPoint(const double x, const DSample &y)
+{
+    DMat d(1, 3);
+    string usingCmd, tmpFileName;
+
+    d(0, 0)     = x;
+    d(0, 1)     = y[central];
+    d(0, 2)     = sqrt(y.variance());
+    tmpFileName = dumpToTmpFile(d);
+    pushTmpFile(tmpFileName);
+    setCommand("'" + tmpFileName + "' u 1:2:3 w yerr");
+}
+
+PlotPoint::PlotPoint(const DSample &x, const DSample &y)
+{
+    DMat d(1, 4);
+    string usingCmd, tmpFileName;
+
+    d(0, 0)     = x[central];
+    d(0, 2)     = y[central];
+    d(0, 1)     = sqrt(x.variance());
+    d(0, 3)     = sqrt(y.variance());
+    tmpFileName = dumpToTmpFile(d);
+    pushTmpFile(tmpFileName);
+    setCommand("'" + tmpFileName + "' u 1:3:2:4 w xyerr");
+}
+
+
 // PlotLine constructor ////////////////////////////////////////////////////////
 PlotLine::PlotLine(const DVec &x, const DVec &y)
 {
diff --git a/lib/Core/Plot.hpp b/lib/Core/Plot.hpp
index 1c2901c..af3a6b4 100644
--- a/lib/Core/Plot.hpp
+++ b/lib/Core/Plot.hpp
@@ -98,6 +98,18 @@ public:
     virtual ~PlotData(void) = default;
 };
 
+class PlotPoint: public PlotObject
+{
+public:
+    // constructor
+    PlotPoint(const double  x,  const double  y);
+    PlotPoint(const DSample &x, const double  y);
+    PlotPoint(const double  x,  const DSample &y);
+    PlotPoint(const DSample &x, const DSample &y);
+    // destructor
+    virtual ~PlotPoint(void) = default;
+};
+
 class PlotHLine: public PlotObject
 {
 public:
diff --git a/physics/2pt-fit.cpp b/physics/2pt-fit.cpp
index 739f18f..6ba59be 100644
--- a/physics/2pt-fit.cpp
+++ b/physics/2pt-fit.cpp
@@ -3,6 +3,7 @@
 #include <LatAnalyze/Core/Plot.hpp>
 #include <LatAnalyze/Functional/CompiledModel.hpp>
 #include <LatAnalyze/Io/Io.hpp>
+#include <LatAnalyze/Numerical/DWT.hpp>
 #include <LatAnalyze/Numerical/MinuitMinimizer.hpp>
 #include <LatAnalyze/Numerical/NloptMinimizer.hpp>
 #include <LatAnalyze/Physics/CorrelatorFitter.hpp>
@@ -23,7 +24,7 @@ int main(int argc, char *argv[])
 {
     // parse arguments /////////////////////////////////////////////////////////
     OptParser            opt;
-    bool                 parsed, doPlot, doHeatmap, doCorr, fold, doScan;
+    bool                 parsed, doLaplace, doPlot, doHeatmap, doCorr, fold, doScan;
     string               corrFileName, model, outFileName, outFmt, savePlot;
     Index                ti, tf, shift, nPar, thinning;
     double               svdTol;
@@ -52,6 +53,8 @@ int main(int argc, char *argv[])
                   "only do the uncorrelated fit");
     opt.addOption("" , "fold"   , OptParser::OptType::trigger, true,
                   "fold the correlator");
+    opt.addOption("l" , "laplace"   , OptParser::OptType::trigger, true,
+                  "apply Laplace filter to the correlator");
     opt.addOption("p", "plot"     , OptParser::OptType::trigger, true,
                   "show the fit plot");
     opt.addOption("h", "heatmap"  , OptParser::OptType::trigger, true,
@@ -74,6 +77,7 @@ int main(int argc, char *argv[])
     ti           = opt.optionValue<Index>("ti");
     tf           = opt.optionValue<Index>("tf");
     thinning     = opt.optionValue<Index>("t");
+    doLaplace    = opt.gotOption("l");
     shift        = opt.optionValue<Index>("s");
     model        = opt.optionValue("m");
     nPar         = opt.optionValue<Index>("nPar");
@@ -110,6 +114,22 @@ int main(int argc, char *argv[])
     nt      = corr[central].rows();
     corr    = corr.block(0, 0, nt, 1);
     corr    = CorrelatorUtils::shift(corr, shift);
+
+    if (doLaplace)
+    {
+        vector<double> filter = {1., -2., 1.};
+        DVec           buf;
+
+        FOR_STAT_ARRAY(corr, s)
+        {
+            DWT::filterConvolution(buf, corr[s], filter, 1);
+            corr[s] = buf;
+        }
+    }
+    if (fold)
+    {
+        corr = CorrelatorUtils::fold(corr);
+    }
     
     // make model //////////////////////////////////////////////////////////////
     CorrelatorFitter fitter(corr);
@@ -283,7 +303,7 @@ int main(int argc, char *argv[])
                 DMat  id = DMat::Identity(n, n),
                       var = fitter.data().getFitVarMat();
                 
-                p << PlotMatrix(Math::varToCorr(var));
+                p << PlotCorrMatrix(Math::varToCorr(var));
                 p << Caption("correlation matrix");
                 p.display();
                 if (svdTol > 0.)