Method eigen

SRC/analysis/analysis/DirectIntegrationAnalysis.cpp:284–387

}

int 
DirectIntegrationAnalysis::eigen(int numMode, bool generalized, bool findSmallest)
{
    if (theAnalysisModel == 0 || theEigenSOE == 0) {
      opserr << "WARNING DirectIntegrationAnalysis::eigen() - no EigenSOE has been set\n";
      return -1;
    }

    int result = 0;
    Domain *the_Domain = this->getDomainPtr();

    result = theAnalysisModel->eigenAnalysis(numMode, generalized, findSmallest);

    int stamp = the_Domain->hasDomainChanged();

    if (stamp != domainStamp) {
      domainStamp = stamp;
  
      result = this->domainChanged();
      
      if (result < 0) {
	     opserr << "DirectIntegrationAnalysis::eigen() - domainChanged failed";
	return -1;
      }	
    }


    //
    // zero A and M
    //
    theEigenSOE->zeroA();
    theEigenSOE->zeroM();

    //
    // form K
    //


    FE_EleIter &theEles = theAnalysisModel->getFEs();    
    FE_Element *elePtr;

    while((elePtr = theEles()) != 0) {
      elePtr->zeroTangent();
      elePtr->addKtToTang(1.0);
      if (theEigenSOE->addA(elePtr->getTangent(0), elePtr->getID()) < 0) {
	opserr << "WARNING DirectIntegrationAnalysis::eigen() -";
	opserr << " failed in addA for ID " << elePtr->getID();	    
	result = -2;
      }
    }

    //
    // if generalized is true, form M
    //

    if (generalized == true) {
      //      int result = 0;
      FE_EleIter &theEles2 = theAnalysisModel->getFEs();