[DAEmode] several minor improvments and fixes for events

 - fixes the when equations generation
 - fixes the event handling at startTime
 - minor improvments

Belonging to [master]:
  - #2259
  - OpenModelica/OpenModelica-testsuite#871

Author: Willi Braun

Compiler/SimCode/SimCodeMain.mo

@@ -1161,7 +1161,7 @@ algorithm
     daeVars := BackendVariable.listVar(varsLst);
     daeEqns := BackendEquation.listEquation(eqnsLst);
     // create SimCode residual equation
-    (daeEquations, uniqueEqIndex, tempVars) := SimCodeUtil.createEquationsfromList(listReverse(eqnsLst), varsLst, false, uniqueEqIndex, tempVars, inBackendDAE.shared.info);
+    (daeEquations, uniqueEqIndex, tempVars) := SimCodeUtil.createEquationsfromList(listReverse(eqnsLst), varsLst, uniqueEqIndex, tempVars, inBackendDAE.shared.info, true, true);
 
     (uniqueEqIndex, removedEquations) := BackendEquation.traverseEquationArray(BackendDAEUtil.collapseRemovedEqs(inBackendDAE), SimCodeUtil.traversedlowEqToSimEqSystem, (uniqueEqIndex, {}));
     daeEquations := listAppend(daeEquations, removedEquations);

Compiler/SimCode/SimCodeUtil.mo

@@ -5604,7 +5604,7 @@ algorithm
     case (BackendDAE.IF_EQUATION(conditions=conditions, eqnstrue=eqnsLst, eqnsfalse=elseqns, source=source_), _,
           BackendDAE.SHARED(info = ei), _, _, _) equation
       (ifbranches, uniqueEqIndex, tempvars) = createEquationsIfBranch(conditions, eqnsLst, inVars, shared, genDiscrete, iuniqueEqIndex, itempvars);
-      (equations_, uniqueEqIndex, tempvars) = createEquationsfromList(elseqns, inVars, genDiscrete, uniqueEqIndex, tempvars, ei);
+      (equations_, uniqueEqIndex, tempvars) = createEquationsfromList(elseqns, inVars, uniqueEqIndex, tempvars, ei, genDiscrete);
     then ({SimCode.SES_IFEQUATION(uniqueEqIndex, ifbranches, equations_, source_)}, uniqueEqIndex+1, tempvars);
 
     else equation
@@ -5643,7 +5643,7 @@ algorithm
 
     case (condition::conditionList, eqns::eqnsLst, _,
           BackendDAE.SHARED(info = ei), _, _, _) equation
-      (equations_, uniqueEqIndex, tempvars) = createEquationsfromList(eqns, inVars, genDiscrete, iuniqueEqIndex, itempvars, ei);
+      (equations_, uniqueEqIndex, tempvars) = createEquationsfromList(eqns, inVars, iuniqueEqIndex, itempvars, ei, genDiscrete);
       ifbranch = ((condition, equations_));
       (ifbranches, uniqueEqIndex, tempvars) = createEquationsIfBranch(conditionList, eqnsLst, inVars, shared, genDiscrete, uniqueEqIndex, tempvars);
       ifbranches = ifbranch::ifbranches;
@@ -5658,10 +5658,13 @@ end createEquationsIfBranch;
 public function createEquationsfromList
   input list<BackendDAE.Equation> inEquations;
   input list<BackendDAE.Var> inVars;
-  input Boolean genDiscrete;
   input Integer iuniqueEqIndex;
   input list<SimCodeVar.SimVar> itempvars;
   input BackendDAE.ExtraInfo iextra;
+  input Boolean genDiscrete = false;
+  input Boolean includeWhen = false;
+  input Boolean skipDiscInZc = false;
+  input Boolean skipDiscInAlgorithm = false;
   output list<SimCode.SimEqSystem> equations_;
   output Integer ouniqueEqIndex;
   output list<SimCodeVar.SimVar> otempvars;
@@ -5689,7 +5692,7 @@ algorithm
       (BackendDAE.DAE({syst as BackendDAE.EQSYSTEM(matching=BackendDAE.MATCHING(comps=comps))}, shared)) =
           BackendDAEUtil.transformBackendDAE( subsystem_dae, SOME((BackendDAE.NO_INDEX_REDUCTION(),
                                               BackendDAE.ALLOW_UNDERCONSTRAINED())), NONE(), NONE() );
-      (equations_, _, uniqueEqIndex, tempvars) = createEquations(false, false, genDiscrete, false, syst, shared, comps, iuniqueEqIndex, itempvars);
+      (equations_, _, uniqueEqIndex, tempvars) = createEquations(includeWhen, skipDiscInZc, genDiscrete, skipDiscInAlgorithm, syst, shared, comps, iuniqueEqIndex, itempvars);
     then (equations_, uniqueEqIndex, tempvars);
 
     else equation
@@ -5963,7 +5966,7 @@ algorithm
         eqnLst = List.threadMap2(expl, expl1, BackendEquation.generateEquation, source, eqKind);
 
         // generate SimCode equations therefore
-        (eqSystlst, uniqueEqIndex, tempvars) = createEquationsfromList(eqnLst, inVars, genDiscrete, iuniqueEqIndex, itempvars, iextra);
+        (eqSystlst, uniqueEqIndex, tempvars) = createEquationsfromList(eqnLst, inVars, iuniqueEqIndex, itempvars, iextra, genDiscrete);
       then
         (eqSystlst, uniqueEqIndex, tempvars);
 
@@ -5983,7 +5986,7 @@ algorithm
         eqnLst = List.threadMap2(expl, expl1, BackendEquation.generateEquation, source, eqKind);
 
         // generate SimCode equations therefore
-        (eqSystlst, uniqueEqIndex,_) = createEquationsfromList(eqnLst, inVars, genDiscrete, iuniqueEqIndex, itempvars, iextra);
+        (eqSystlst, uniqueEqIndex,_) = createEquationsfromList(eqnLst, inVars, iuniqueEqIndex, itempvars, iextra, genDiscrete);
       then
         (eqSystlst, uniqueEqIndex, itempvars);
 

Compiler/Template/CodegenC.tpl

@@ -897,7 +897,6 @@ template simulationFile_dae(SimCode simCode)
      <<
      /* DAE residuals */
      <%simulationFileHeader(fileNamePrefix)%>
-     #include "<%fileNamePrefix%>_16dae.h"
 
      #ifdef __cplusplus
      extern "C" {

SimulationRuntime/c/simulation/solver/ida_solver.c

@@ -723,6 +723,13 @@ ida_event_update(DATA* data, threadData_t *threadData)
 
       /* get initial step to provide a direction of the solution */
       IDAGetActualInitStep(idaData->ida_mem, &init_h);
+      /* provide a feasible step-size if it's too small */
+      if (init_h < DBL_EPSILON){
+        init_h = DBL_EPSILON;
+        IDASetInitStep(idaData->ida_mem, init_h);
+        infoStreamPrint(LOG_SOLVER, 0, "##IDA## corrected step-size at %.15g", init_h);
+      }
+
       /* increase limits of the non-linear solver */
       IDASetMaxNumStepsIC(idaData->ida_mem, 2*data->modelData->nStates*10);
       IDASetMaxNumJacsIC(idaData->ida_mem, 2*data->modelData->nStates*10);
@@ -738,7 +745,7 @@ ida_event_update(DATA* data, threadData_t *threadData)
       if (checkIDAflag(flag)){
         infoStreamPrint(LOG_SOLVER, 0, "##IDA## first event iteration failed. Start next try without line search!");
         IDASetLineSearchOffIC(idaData->ida_mem, TRUE);
-        flag = IDACalcIC(idaData->ida_mem, IDA_YA_YDP_INIT, data->localData[0]->timeValue+1);
+        flag = IDACalcIC(idaData->ida_mem, IDA_YA_YDP_INIT, data->localData[0]->timeValue+data->simulationInfo->tolerance);
         IDAGetNumNonlinSolvIters(idaData->ida_mem, &nonLinIters);
         infoStreamPrint(LOG_SOLVER, 0, "##IDA## IDACalcIC run status %d.\nIterations : %ld\n", flag, nonLinIters);
         if (checkIDAflag(flag)){
@@ -757,6 +764,9 @@ ida_event_update(DATA* data, threadData_t *threadData)
       // and  also algebraic vars
       data->simulationInfo->daeModeData->setAlgebraicDAEVars(data, threadData, idaData->states + data->modelData->nStates);
       memcpy(data->localData[0]->realVars + data->modelData->nStates, idaData->statesDer, sizeof(double)*data->modelData->nStates);
+
+      /* reset initial step size again to default */
+      IDASetInitStep(idaData->ida_mem, 0.0);
     }
   }
   else{
@@ -890,7 +900,7 @@ ida_solver_step(DATA* data, threadData_t *threadData, SOLVER_INFO* solverInfo)
   /* Calculate steps until TOUT is reached */
   if (idaData->internalSteps)
   {
-    /* If dasslsteps is selected, the dassl run to stopTime or next sample event */
+    /* If internalSteps are selected, let IDA run to stopTime or next sample event */
     if (data->simulationInfo->nextSampleEvent < data->simulationInfo->stopTime)
     {
       tout = data->simulationInfo->nextSampleEvent;