Method formTangent

SRC/analysis/integrator/KRAlphaExplicit.cpp:287–315

int KRAlphaExplicit::formTangent(int statFlag)
{
    statusFlag = statFlag;
    
    // only update tangent if domain has changed
    if (initAlphaMatrices) {
        LinearSOE *theLinSOE = this->getLinearSOE();
        AnalysisModel *theModel = this->getAnalysisModel();
        if (theLinSOE == 0 || theModel == 0)  {
            opserr << "WARNING KRAlphaExplicit::formTangent() - ";
            opserr << "no LinearSOE or AnalysisModel has been set\n";
            return -1;
        }
        
        theLinSOE->zeroA();
        
        int size = theLinSOE->getNumEqn();
        ID id(size);
        for (int i=1; i<size; i++)  {
            id(i) = id(i-1) + 1;
        }
        if (theLinSOE->addA(*Mhat, id) < 0)  {
            opserr << "WARNING KRAlphaExplicit::formTangent() - ";
            opserr << "failed to add Mhat to A\n";
            return -2;
        }
    }
    return 0;
}


int KRAlphaExplicit::formEleTangent(FE_Element *theEle)