Change input tol of Newton solver to 2-norm

ticket:3923

SimulationRuntime/c/simulation/solver/model_help.c

@@ -53,8 +53,8 @@
 int maxEventIterations = 20;
 double linearSparseSolverMaxDensity = 0.2;
 int linearSparseSolverMinSize = 4001;
-double newtonXTol = 1e-24;
-double newtonFTol = 1e-24;
+double newtonXTol = 1e-12;
+double newtonFTol = 1e-12;
 const size_t SIZERINGBUFFER = 3;
 int compiledInDAEMode = 0;
 

SimulationRuntime/c/simulation/solver/nonlinearSolverHomotopy.c

@@ -150,8 +150,8 @@ int allocateHomotopyData(int size, void** voiddata)
   data->initialized = 0;
   data->n = size;
   data->m = size + 1;
-  data->xtol = newtonXTol;
-  data->ftol = newtonFTol;
+  data->xtol = newtonXTol*newtonXTol;
+  data->ftol = newtonFTol*newtonFTol;
 
   data->error_f = 0;
 
@@ -1279,7 +1279,7 @@ static int newtonAlgorithm(DATA_HOMOTOPY* solverData, double* x)
 
 
     /* debug information */
-    debugString(LOG_NLS_V, "error measurements:");
+    debugString(LOG_NLS_V, "error measurements (squared):");
     debugDouble(LOG_NLS_V, "delta_x        =", delta_x);
     debugDouble(LOG_NLS_V, "delta_x_scaled =", delta_x_scaled);
     debugDouble(LOG_NLS_V, "eps_x          =", solverData->xtol);

SimulationRuntime/c/util/simulation_options.c

@@ -148,8 +148,8 @@ const char *FLAG_DESC[FLAG_MAX+1] = {
   /* FLAG_MAX_ORDER */             "value specifies maximum integration order, used by dassl solver",
   /* FLAG_MAX_STEP_SIZE */         "value specifies maximum absolute step size, used by dassl solver",
   /* FLAG_MEASURETIMEPLOTFORMAT */ "value specifies the output format of the measure time functionality",
-  /* FLAG_NEWTON_FTOL */           "[double (default 1e-24)] tolerance for accepting accuracy in Newton solver",
-  /* FLAG_NEWTON_XTOL */           "[double (default 1e-24)] tolerance for updating solution vector in Newton solver",
+  /* FLAG_NEWTON_FTOL */           "[double (default 1e-12)] tolerance respecting residuals for updating solution vector in Newton solver",
+  /* FLAG_NEWTON_XTOL */           "[double (default 1e-12)] tolerance respecting newton correction (delta_x) for updating solution vector in Newton solver",
   /* FLAG_NEWTON_STRATEGY */       "value specifies the damping strategy for the newton solver",
   /* FLAG_NLS */                   "value specifies the nonlinear solver",
   /* FLAG_NLS_INFO */              "outputs detailed information about solving process of non-linear systems into csv files.",
@@ -290,11 +290,13 @@ const char *FLAG_DETAILED_DESC[FLAG_MAX+1] = {
   "  * gif\n"
   "  * ...",
   /* FLAG_NEWTON_FTOL */
-  "  Tolerance for accepting accuracy in Newton solver."
-  "  The value is a Double with default value 1e-24.",
+  "  Tolerance respecting residuals for updating solution vector in Newton solver."
+  "  Solution is accepted if the (scaled) 2-norm of the residuals is smaller than the tolerance newtonFTol and the (scaled) newton correction (delta_x) is smaller than the tolerance newtonXTol."
+  "  The value is a Double with default value 1e-12.",
   /* FLAG_NEWTON_XTOL */
-  "  Tolerance for updating solution vector in Newton solver."
-  "  The value is a Double with default value 1e-24.",
+  "  Tolerance respecting newton correction (delta_x) for updating solution vector in Newton solver."
+  "  Solution is accepted if the (scaled) 2-norm of the residuals is smaller than the tolerance newtonFTol and the (scaled) newton correction (delta_x) is smaller than the tolerance newtonXTol."
+  "  The value is a Double with default value 1e-12.",
   /* FLAG_NEWTON_STRATEGY */
   "  Value specifies the damping strategy for the newton solver.",
   /* FLAG_NLS */