Method update

DEVELOPER/integrator/Trapezoidal.cpp:300–333

int Trapezoidal::update(const Vector &deltaU)
{
    AnalysisModel *theModel = this->getAnalysisModel();
    if (theModel == 0)  {
        opserr << "WARNING Trapezoidal::update() - no AnalysisModel set\n";
        return -1;
    }	
    
    // check domainChanged() has been called, i.e. Ut will not be zero
    if (Ut == 0)  {
        opserr << "WARNING Trapezoidal::update() - domainChange() failed or not called\n";
        return -2;
    }	
    
    // check deltaU is of correct size
    if (deltaU.Size() != U->Size())  {
        opserr << "WARNING Trapezoidal::update() - Vectors of incompatible size ";
        opserr << " expecting " << U->Size() << " obtained " << deltaU.Size() << endln;
        return -3;
    }
    
    (*U) += deltaU;
    Udot->addVector(1.0, deltaU, c2);
    Udotdot->addVector(1.0, deltaU, c3);

    // update the response at the DOFs
    theModel->setResponse(*U,*Udot,*Udotdot);
    if (theModel->updateDomain() < 0)  {
      opserr << "Trapezoidal::update() - failed to update the domain\n";
      return -4;
    }
    
    return 0;
}    


int Trapezoidal::sendSelf(int cTag, Channel &theChannel)