diff -r aa1bff27656c src/core/random-variable.cc
--- a/src/core/random-variable.cc	Tue Mar 03 18:52:00 2009 +0000
+++ b/src/core/random-variable.cc	Tue Mar 03 15:30:46 2009 -0500
@@ -95,6 +95,7 @@
   virtual double  GetValue() = 0;
   virtual uint32_t GetInteger();
   virtual RandomVariableBase*   Copy(void) const = 0;
+  virtual void SerializeTo (std::ostream &os) const = 0;
 
 protected:
   RngStream* m_generator;  //underlying generator being wrapped
@@ -207,6 +208,7 @@
   virtual double GetValue(double s, double l);
   
   virtual RandomVariableBase*  Copy(void) const;
+  virtual void SerializeTo (std::ostream &os) const;
 
 private:
   double m_min;
@@ -257,6 +259,11 @@
   return new UniformVariableImpl(*this);
 }
 
+void UniformVariableImpl::SerializeTo (std::ostream& os) const
+{
+  os << "Uniform:" << GetMin () << ":" << GetMax ();
+}
+
 UniformVariable::UniformVariable()
   : RandomVariable (UniformVariableImpl ())
 {}
@@ -309,6 +316,7 @@
   virtual double  GetValue();
   virtual uint32_t GetInteger();
   virtual RandomVariableBase*   Copy(void) const;
+  virtual void SerializeTo (std::ostream& os) const;
 private:
   double m_const;
 };
@@ -338,6 +346,11 @@
 RandomVariableBase* ConstantVariableImpl::Copy() const
 {
   return new ConstantVariableImpl(*this);
+}
+
+void ConstantVariableImpl::SerializeTo (std::ostream& os) const
+{
+  os << "Constant:" << m_const;
 }
 
 ConstantVariable::ConstantVariable()
@@ -393,6 +406,7 @@
    */
   virtual double GetValue();
   virtual RandomVariableBase*  Copy(void) const;
+  virtual void SerializeTo (std::ostream& os) const;
 private:
   double m_min;
   double m_max;
@@ -439,6 +453,12 @@
   return new SequentialVariableImpl(*this);
 }
 
+void SequentialVariableImpl::SerializeTo (std::ostream& os) const
+{
+  // XXX: support other distributions
+  os.setstate (std::ios_base::badbit);
+}
+
 SequentialVariable::SequentialVariable(double f, double l, double i, uint32_t c)
   : RandomVariable (SequentialVariableImpl (f, l, i, c))
 {}
@@ -484,6 +504,7 @@
    */
   virtual double GetValue();
   virtual RandomVariableBase* Copy(void) const;
+  virtual void SerializeTo (std::ostream& os) const;
 
 private:
   double m_mean;  // Mean value of RV
@@ -519,6 +540,12 @@
 RandomVariableBase* ExponentialVariableImpl::Copy() const
 {
   return new ExponentialVariableImpl(*this);
+}
+
+void ExponentialVariableImpl::SerializeTo (std::ostream& os) const
+{
+  // XXX: support other distributions
+  os.setstate (std::ios_base::badbit);
 }
 
 ExponentialVariable::ExponentialVariable()
@@ -578,6 +605,7 @@
    */
   virtual double GetValue();
   virtual RandomVariableBase* Copy() const;
+  virtual void SerializeTo (std::ostream& os) const;
 
 private:
   double m_mean;  // Mean value of RV
@@ -621,6 +649,12 @@
   return new ParetoVariableImpl(*this);
 }
 
+void ParetoVariableImpl::SerializeTo (std::ostream& os) const
+{
+  // XXX: support other distributions
+  os.setstate (std::ios_base::badbit);
+}
+
 ParetoVariable::ParetoVariable ()
   : RandomVariable (ParetoVariableImpl ())
 {}
@@ -682,6 +716,7 @@
    */
   virtual double GetValue();
   virtual RandomVariableBase* Copy(void) const;
+  virtual void SerializeTo (std::ostream& os) const;
 
 private:
   double m_mean;  // Mean value of RV
@@ -720,6 +755,12 @@
   return new WeibullVariableImpl(*this);
 }
 
+void WeibullVariableImpl::SerializeTo (std::ostream& os) const
+{
+  // XXX: support other distributions
+  os.setstate (std::ios_base::badbit);
+}
+
 WeibullVariable::WeibullVariable()
   : RandomVariable (WeibullVariableImpl ())
 {}
@@ -762,6 +803,7 @@
    */
   virtual double GetValue();
   virtual RandomVariableBase* Copy(void) const;
+  virtual void SerializeTo (std::ostream& os) const;
 
   double GetMean (void) const;
   double GetVariance (void) const;
@@ -839,6 +881,16 @@
   return new NormalVariableImpl(*this);
 }
 
+void NormalVariableImpl::SerializeTo (std::ostream& os) const
+{
+  os << "Normal:" << GetMean () << ":" << GetVariance ();
+  double bound = GetBound ();
+  if (bound != NormalVariableImpl::INFINITE_VALUE)
+    {
+      os << ":" << bound;
+    }
+}
+
 double
 NormalVariableImpl::GetMean (void) const
 {
@@ -883,6 +935,7 @@
    */
   virtual double GetValue();
   virtual RandomVariableBase* Copy(void) const;
+  virtual void SerializeTo (std::ostream& os) const;
   /**
    * \brief Specifies a point in the empirical distribution
    * \param v The function value for this point
@@ -978,6 +1031,12 @@
   return new EmpiricalVariableImpl(*this);
 }
 
+void EmpiricalVariableImpl::SerializeTo (std::ostream& os) const
+{
+  // XXX: support other distributions
+  os.setstate (std::ios_base::badbit);
+}
+
 void EmpiricalVariableImpl::CDF(double v, double c)
 { // Add a new empirical datapoint to the empirical cdf
   // NOTE.   These MUST be inserted in non-decreasing order
@@ -1034,6 +1093,7 @@
   IntEmpiricalVariableImpl();
   
   virtual RandomVariableBase* Copy(void) const;
+  virtual void SerializeTo (std::ostream& os) const;
   /**
    * \return An integer value from this empirical distribution
    */
@@ -1053,6 +1113,12 @@
 RandomVariableBase* IntEmpiricalVariableImpl::Copy() const
 {
   return new IntEmpiricalVariableImpl(*this);
+}
+
+void IntEmpiricalVariableImpl::SerializeTo (std::ostream& os) const
+{
+  // XXX: support other distributions
+  os.setstate (std::ios_base::badbit);
 }
 
 double IntEmpiricalVariableImpl::Interpolate(double c1, double c2,
@@ -1091,6 +1157,7 @@
    */
   virtual double GetValue();
   virtual RandomVariableBase* Copy(void) const;
+  virtual void SerializeTo (std::ostream& os) const;
 private:
   uint32_t   count;
   uint32_t   next;
@@ -1118,6 +1185,12 @@
   return new DeterministicVariableImpl(*this);
 }
 
+void DeterministicVariableImpl::SerializeTo (std::ostream& os) const
+{
+  // XXX: support other distributions
+  os.setstate (std::ios_base::badbit);
+}
+
 DeterministicVariable::DeterministicVariable(double* d, uint32_t c)
   : RandomVariable (DeterministicVariableImpl (d, c))
 {}
@@ -1138,6 +1211,7 @@
    */
   virtual double GetValue ();
   virtual RandomVariableBase* Copy(void) const;
+  virtual void SerializeTo (std::ostream& os) const;
 
 private:
   double m_mu;
@@ -1148,6 +1222,12 @@
 RandomVariableBase* LogNormalVariableImpl::Copy () const
 {
   return new LogNormalVariableImpl (m_mu, m_sigma);
+}
+
+void LogNormalVariableImpl::SerializeTo (std::ostream& os) const
+{
+  // XXX: support other distributions
+  os.setstate (std::ios_base::badbit);
 }
 
 LogNormalVariableImpl::LogNormalVariableImpl (double mu, double sigma)
@@ -1240,6 +1320,7 @@
    */
   virtual double GetValue();
   virtual RandomVariableBase*  Copy(void) const;
+  virtual void SerializeTo (std::ostream& os) const;
 
 private:
   double m_min;
@@ -1279,6 +1360,12 @@
   return new TriangularVariableImpl(*this);
 }
 
+void TriangularVariableImpl::SerializeTo (std::ostream& os) const
+{
+  // XXX: support other distributions
+  os.setstate (std::ios_base::badbit);
+}
+
 TriangularVariable::TriangularVariable()
   : RandomVariable (TriangularVariableImpl ())
 {}
@@ -1290,31 +1377,7 @@
 std::ostream &operator << (std::ostream &os, const RandomVariable &var)
 {
   RandomVariableBase *base = var.Peek ();
-  ConstantVariableImpl *constant = dynamic_cast<ConstantVariableImpl *> (base);
-  if (constant != 0)
-    {
-      os << "Constant:" << constant->GetValue ();
-      return os;
-    }
-  UniformVariableImpl *uniform = dynamic_cast<UniformVariableImpl *> (base);
-  if (uniform != 0)
-    {
-      os << "Uniform:" << uniform->GetMin () << ":" << uniform->GetMax ();
-      return os;
-    }
-  NormalVariableImpl *normal = dynamic_cast<NormalVariableImpl *> (base);
-  if (normal != 0)
-    {
-      os << "Normal:" << normal->GetMean () << ":" << normal->GetVariance ();
-      double bound = normal->GetBound ();
-      if (bound != NormalVariableImpl::INFINITE_VALUE)
-        {
-          os << ":" << bound;
-        }
-      return os;
-    }
-  // XXX: support other distributions
-  os.setstate (std::ios_base::badbit);
+  base->SerializeTo (os);
   return os;
 }
 std::istream &operator >> (std::istream &is, RandomVariable &var)