Method update

SRC/analysis/integrator/HHTHSFixedNumIter.cpp:421–490

int HHTHSFixedNumIter::update(const Vector &deltaU)
{
    AnalysisModel *theModel = this->getAnalysisModel();
    if (theModel == 0)  {
        opserr << "WARNING HHTHSFixedNumIter::update() - no AnalysisModel set\n";
        return -1;
    }
    ConvergenceTest *theTest = this->getConvergenceTest();
    if (theTest == 0)  {
        opserr << "WARNING HHTHSFixedNumIter::update() - no ConvergenceTest set\n";
        return -2;
    }
    
    // check domainChanged() has been called, i.e. Ut will not be zero
    if (Ut == 0)  {
        opserr << "WARNING HHTHSFixedNumIter::update() - domainChange() failed or not called\n";
        return -3;
    }
    
    // check deltaU is of correct size
    if (deltaU.Size() != U->Size())  {
        opserr << "WARNING HHTHSFixedNumIter::update() - Vectors of incompatible size ";
        opserr << " expecting " << U->Size() << " obtained " << deltaU.Size() << endln;
        return -4;
    }
    
    // get interpolation location and scale displacement increment 
    x = (double) theTest->getNumTests()/theTest->getMaxNumTests();
    if (polyOrder == 1)  {
        (*scaledDeltaU) = x*((*U)+deltaU) - (x-1.0)*(*Ut)  - (*U);
    }
    else if (polyOrder == 2)  {
        (*scaledDeltaU) = x*(x+1.0)/2.0*((*U)+deltaU) - (x-1.0)*(x+1.0)*(*Ut) 
                        + (x-1.0)*x/2.0*(*Utm1) - (*U);
    }
    else if (polyOrder == 3)  {
        (*scaledDeltaU) = x*(x+1.0)*(x+2.0)/6.0*((*U)+deltaU) - (x-1.0)*(x+1.0)*(x+2.0)/2.0*(*Ut)
                        + (x-1.0)*x*(x+2.0)/2.0*(*Utm1) - (x-1.0)*x*(x+1.0)/6.0*(*Utm2) - (*U);
    }
    else  {
        opserr << "WARNING HHTHSFixedNumIter::update() - polyOrder > 3 not supported\n";
        return -5;
    }
    
    // determine the response at t+deltaT
    U->addVector(1.0, *scaledDeltaU, c1);
    
    Udot->addVector(1.0, *scaledDeltaU, c2);
    
    Udotdot->addVector(1.0, *scaledDeltaU, c3);
    
    // determine response at t+alpha*deltaT
    (*Ualpha) = *Ut;
    Ualpha->addVector((1.0-alphaF), *U, alphaF);
    
    (*Ualphadot) = *Utdot;
    Ualphadot->addVector((1.0-alphaF), *Udot, alphaF);