5.8. eigen command

eigen(solver='-genBandArpack', numEigenvalues)

Eigen value analysis. Return a list of eigen values.

numEigenvalues (int)

number of eigenvalues required

solver (str)

optional string detailing type of solver: '-genBandArpack', '-fullGenLapack', (optional)

Note

  1. The eigenvectors are stored at the nodes and can be printed out using a Node Recorder, the nodeEigenvector command, or the Print command.

  2. The default eigensolver is able to solve only for N-1 eigenvalues, where N is the number of inertial DOFs. When running into this limitation the -fullGenLapack solver can be used instead of the default Arpack solver.

  3. The -fullGenLapack option is VERY SLOW for moderate to large models