[Reactor] Added ability to set the CVODES "MaxErrTestFails" variable

Increasing this value (from the default of 7) will sometimes allow CVODES to
find solutions to problems that previously caused it to fail.

include/cantera/numerics/CVodesIntegrator.h

@@ -70,6 +70,7 @@ public:
     virtual void setMaxStepSize(double hmax);
     virtual void setMinStepSize(double hmin);
     virtual void setMaxSteps(int nmax);
+    virtual void setMaxErrTestFails(int n);
     virtual void setBandwidth(int N_Upper, int N_Lower) {
         m_mupper = N_Upper;
         m_mlower = N_Lower;
@@ -111,6 +112,7 @@ private:
     size_t m_nabs;
     double m_hmax, m_hmin;
     int m_maxsteps;
+    int m_maxErrTestFails;
     FuncData* m_fdata;
     N_Vector*  m_yS;
     size_t m_np;

include/cantera/numerics/Integrator.h

@@ -184,6 +184,11 @@ public:
         warn("setMinStepSize");
     }
 
+    //! Set the maximum permissible number of error test failures
+    virtual void setMaxErrTestFails(int n) {
+        warn("setMaxErrTestFails");
+    }
+
     virtual void setMaxSteps(int nmax) {
         warn("setMaxStep");
     }

include/cantera/zeroD/ReactorNet.h

@@ -46,6 +46,13 @@ public:
         m_init = false;
     }
 
+    //! Set the maximum number of error test failures permitted by the CVODES
+    //! integrator in a single time step.
+    void setMaxErrTestFails(int nmax) {
+        m_maxErrTestFails = nmax;
+        m_init = false;
+    }
+
     void setTolerances(doublereal rtol, doublereal atol) {
         if (rtol >= 0.0) {
             m_rtol = rtol;
@@ -189,6 +196,7 @@ protected:
     doublereal m_rtol, m_rtolsens;
     doublereal m_atols, m_atolsens;
     doublereal m_maxstep;
+    int m_maxErrTestFails;
     bool m_verbose;
     size_t m_ntotpar;
     std::vector<size_t> m_nparams;

interfaces/cython/cantera/_cantera.pxd

@@ -322,6 +322,7 @@ cdef extern from "cantera/zeroD/ReactorNet.h":
         double rtol()
         double atol()
         void setMaxTimeStep(double)
+        void setMaxErrTestFails(int)
         cbool verbose()
         void setVerbose(cbool)
         size_t neq()

interfaces/cython/cantera/reactor.pyx

@@ -729,6 +729,14 @@ cdef class ReactorNet:
         """
         self.net.setMaxTimeStep(t)
 
+    property max_err_test_fails:
+        """
+        The maximum number of error test failures permitted by the CVODES
+        integrator in a single time step.
+        """
+        def __set__(self, n):
+            self.net.setMaxErrTestFails(n)
+
     property rtol:
         """
         The relative error tolerance used while integrating the reactor

src/numerics/CVodeInt.h

@@ -60,6 +60,7 @@ public:
     virtual void setMaxStepSize(double hmax);
     virtual void setMinStepSize(double hmin);
     virtual void setMaxSteps(int nmax);
+    virtual void setMaxErrTestFails(int nmax) {}
 
 private:
 

src/numerics/CVodesIntegrator.cpp

@@ -129,6 +129,7 @@ CVodesIntegrator::CVodesIntegrator() :
     m_hmax(0.0),
     m_hmin(0.0),
     m_maxsteps(20000),
+    m_maxErrTestFails(0),
     m_fdata(0),
     m_np(0),
     m_mupper(0), m_mlower(0),
@@ -239,6 +240,14 @@ void CVodesIntegrator::setMaxSteps(int nmax)
     }
 }
 
+void CVodesIntegrator::setMaxErrTestFails(int n)
+{
+    m_maxErrTestFails = n;
+    if (m_cvode_mem) {
+        CVodeSetMaxErrTestFails(m_cvode_mem, n);
+    }
+}
+
 void CVodesIntegrator::setIterator(IterType t)
 {
     if (t == Newton_Iter) {
@@ -467,6 +476,9 @@ void CVodesIntegrator::applyOptions()
     if (m_hmin > 0) {
         CVodeSetMinStep(m_cvode_mem, m_hmin);
     }
+    if (m_maxErrTestFails > 0) {
+        CVodeSetMaxErrTestFails(m_cvode_mem, m_maxErrTestFails);
+    }
 }
 
 void CVodesIntegrator::integrate(double tout)

src/zeroD/ReactorNet.cpp

@@ -14,7 +14,7 @@ ReactorNet::ReactorNet() : Cantera::FuncEval(), m_nr(0), m_nreactors(0),
     m_integ(0), m_time(0.0), m_init(false),
     m_nv(0), m_rtol(1.0e-9), m_rtolsens(1.0e-4),
     m_atols(1.0e-15), m_atolsens(1.0e-4),
-    m_maxstep(-1.0),
+    m_maxstep(-1.0), m_maxErrTestFails(0),
     m_verbose(false), m_ntotpar(0)
 {
 #ifdef DEBUG_MODE
@@ -133,6 +133,7 @@ void ReactorNet::initialize()
     m_integ->setTolerances(m_rtol, neq(), DATA_PTR(m_atol));
     m_integ->setSensitivityTolerances(m_rtolsens, m_atolsens);
     m_integ->setMaxStepSize(m_maxstep);
+    m_integ->setMaxErrTestFails(m_maxErrTestFails);
     if (m_verbose) {
         sprintf(buf, "Number of equations: %s\n", int2str(neq()).c_str());
         writelog(buf);