Method newStep

DEVELOPER/integrator/Trapezoidal.cpp:116–155

int Trapezoidal::newStep(double deltaT)
{
  // check the vectors have been created
  if (U == 0)  {
    opserr << "Trapezoidal::newStep() - domainChange() failed or hasn't been called\n";
    return -3;	
  }

  // get a pointer to the AnalysisModel
  AnalysisModel *theModel = this->getAnalysisModel();

  // set response at t to be that at t+deltaT of previous step
  (*Ut) = *U;        
  (*Utdot) = *Udot;  
  (*Utdotdot) = *Udotdot;

  c1 = 1.0;
  c2 = 2.0/deltaT;
  c3 = 4.0/(deltaT*deltaT);

  (*Udot) *= -1.0;
  
  double a3 = -4.0/deltaT;
  double a4 = -1;
  Udotdot->addVector(a4, *Utdot, a3);
    
  // set the trial response quantities
  theModel->setVel(*Udot);
  theModel->setAccel(*Udotdot);    

  // increment the time to t+deltaT and apply the load
  double time = theModel->getCurrentDomainTime();
  time += deltaT;
  if (theModel->updateDomain(time, deltaT) < 0)  {
    opserr << "Trapezoidal::newStep() - failed to update the domain\n";
    return -4;
  }
  
  return 0;
}


int Trapezoidal::revertToLastStep()