Method newStep

SRC/analysis/integrator/Newmark.cpp:157–261

int Newmark::newStep(double deltaT)
{
    if ((beta == 0 || gamma == 0) && displ != 3)  {
        opserr << "Newmark::newStep() - error in variable\n";
        opserr << "gamma = " << gamma << " beta = " << beta << endln;
        return -1;
    }
    
    if (deltaT < 0.0 || (displ != 3 && deltaT == 0.0))  {
        opserr << "Newmark::newStep() - error in variable\n";
        opserr << "dT = " << deltaT << endln;
        return -2;	
    }

    // get a pointer to the AnalysisModel
    AnalysisModel *theModel = this->getAnalysisModel();
    
    // set the constants
    if (displ == 1)  {
        c1 = 1.0;
        c2 = gamma/(beta*deltaT);
        c3 = 1.0/(beta*deltaT*deltaT);
    } else if (displ == 2) {
	c1 = deltaT*beta/gamma;
	c2 = 1.0;
	c3 = 1.0/(gamma*deltaT);
    } else if (displ == 3) {
        c1 = beta*deltaT*deltaT;
        c2 = gamma*deltaT;
        c3 = 1.0;
    }
    
    if (U == 0)  {
        opserr << "Newmark::newStep() - domainChange() failed or hasn't been called\n";
        return -3;	
    }
    
    // set response at t to be that at t+deltaT of previous step
    /*
    if (converged == true) {
      std::ofstream outfile;

      outfile.open("Newmark.dat",std::ofstream::out | std::ofstream::app);
      int size = U->Size();
      for (int i=0; i<size; i++)
	outfile << (*U)(i) << " ";
      outfile << "\n";
      outfile.close();
    }
    */

    converged = true;

    (*Ut) = *U;        
    (*Utdot) = *Udot;  
    (*Utdotdot) = *Udotdot;
    
    if (displ == 1)  {