Added support for automatic number of output steps by using intermedi…

…ate-output model in DASSL. This can be used by setting a negative value on output step size.

git-svn-id: https://openmodelica.org/svn/OpenModelica/trunk@2665 f25d12d1-65f4-0310-ae8a-bbce733d8d8e

c_runtime/simulation_input.cpp

@@ -79,8 +79,12 @@ void read_commented_value(ifstream &f, string *str);
   read_commented_value(file,stop);
   read_commented_value(file,stepSize);
 
-  // Calculate outputSteps from stepSize, start and stop
+  if (stepSize < 0) { // stepSize < 0 => Automatic number of outputs 
+  	*outputSteps = -1;
+  } else {
+  	// Calculate outputSteps from stepSize, start and stop
   *outputSteps = (long)(int(*stop-*start) /(*stepSize));
+  }
   read_commented_value(file,method);
   int nxchk,nychk,npchk;
   read_commented_value(file,&nxchk);

c_runtime/simulation_result.cpp

@@ -115,7 +115,14 @@ int initializeResult(long numpoints,long nx, long ny, long np)
 {
   maxPoints = numpoints;
 
- simulationResultData = new double[numpoints*(nx*2+ny+1)];
+  if (numpoints < 0 ) { // Automatic number of output steps
+  	cerr << "Warning automatic output steps not supported in OpenModelica yet." << endl;
+  	cerr << "Attempt to solve this by allocating large amount of result data." << endl;
+	numpoints = abs(numpoints);
+	maxPoints = abs(numpoints);   	
+  }
+
+  simulationResultData = new double[numpoints*(nx*2+ny+1)];
   if (!simulationResultData) {
     cerr << "Error allocating simulation result data of size " << numpoints *(nx*2+ny)
 	      << endl;

c_runtime/solver_dasrt.cpp

@@ -119,9 +119,13 @@ int dassl_main(int argc, char**argv,double &start,  double &stop, double &step,
   	atol = tolerance;
   	rtol = tolerance;
   }
-  if (outputSteps != 0) { // Use outputSteps if set, otherwise use step size.
+  if (outputSteps > 0) { // Use outputSteps if set, otherwise use step size.
   	  numpoints = outputSteps;
   	  step = (stop-start)/outputSteps;
+  } if (outputSteps < 0) { // Negative outputSteps means use automatic stepsize  	
+  	info[2]=1; // INFO(3) =1 => intermediate-output mode
+  	numpoints = - (long((stop-start)*10000)+2); // Try to estimate how many points will be used.
+  	step = stop-start; // Only take one step
   } else {
   	if (step == 0) { // outputsteps not defined and zero step, use default 1e-3
   	  step = 1e-3;