 | Arnoldi |
The ArnoldiEigenvalueOptions type exposes the following members.
Properties| Name | Description | |
|---|---|---|
 | ComputeEigenvectors | Gets and sets a boolean specifying whether or not eigenvectors are computed. The default value is true. |
| InitialResiduals | Array of length equal to the order of the poblem. Contains the initial residual vector, possibly from a previous run. If empty or null a ranodm initial residual vector is used. Default is empty. |
| MaxNumArnoldiUpdates | Gets and sets the value of maximum number of Arnoldi update iterations allowed. Default value is 300. |
| NumEigenvalues | Gets and sets the number of eigenvalues to compute. |
| NumLanczosVectors | Gets and sets a number indicating how many Lanczos vectors are generated at each iteration. After the startup phase in which NumEigenvectors Lanczos vectors are generated, the algorithm generates NumLanczosVectors - NumEigenvectors Lanczos vectors at each subsequent update iteration. The default value is Min( 2 * nev, n) where nev is the number of requested eigenvalues and n is the dimension of the problem. |
| SelectedEigenvectors | Logical array of dimension NumEigenvalues. To select the Ritz vector corresponding to a Ritz value D(j), SelectedEigenvectors[j] must be set to true. By default the array is empty and all NumEigenvalues are computed. |
| Tolerance | Gets and sets the tolerance used in the iteration stopping criterion. Iteration stops when the relative accuracy of the Ritz value satifies BOUNDS(I) less than or equal to Bounds(i) <= Tolerance * |Ritz(i)| TOL*ABS(RITZ(I)). The default value is computed machine precision. |
See Also