- EigenSolver
- EigenSolverX
- EigenSolverShur
- EigenSolver2
- EigenSolver2X
- EigenSolver2Shur
- EigenSolver2Blocked
- EigenSolver2ShurBlocked
EigenSolverX
Compute eigenvalues and eigenvectors of a regular square matrix in Expert mode, i.e. with the ability to influence the computation algorithm and the ability to obtain accompanying computation data (lapack function GEEVX).
Computing for type matrix<double>
bool matrix::EigenSolverX(
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Computing for type matrix<float>
bool matrixf::EigenSolverX(
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Computing for type matrix<complex>
bool matrixc::EigenSolverX(
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Computing for type matrix<complexf>
bool matrixcf::EigenSolverX(
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Parameters
balance
[in] Value from the ENUM_EIG_BALANCE enumeration which determines the need and method for balancing the input matrix; it is used to improve the conditioning of the eigenvalues and eigenvectors.
jobv
[in] ENUM_EIG_VECTORS enumeration value which determines the method for computing left and right eigenvectors.
sense
[in] Value from the ENUM_EIG_SENSE enumeration determining the need to compute reciprocal condition numbers.
eigen_values
[out] Vector of eigenvalues.
left_eigenvectors
[out] Matrix of left eigenvectors.
right_eigenvectors
[out] Matrix of right eigenvectors.
shur_matrix
[out] Balanced matrix in Schur form; the matrix is not filled if neither left nor right eigenvectors are computed.
ilo
[out] Subscript of the balanced matrix; the matrix is not filled if no balancing is applied.
ihi
[out] Superscript of the balanced matrix; the matrix is not filled if no balancing is applied.
scale
[out] Vector of details of permutations and scaling when balancing the input matrix.
Details of the permutations and scaling factors applied when balancing A.
If P(j) is the index of the row and column interchanged with row and column j, and D(j) is the scaling factor applied to row and column j, then
scale(j) = P(j), for j = 1,...,ilo-1
= D(j), for j = ilo,...,ihi
= P(j) for j = ihi+1,..., n.
The order in which the interchanges are made is n to ihi+1, then 1 to ilo-1.
ab_norm
[out] 1-norm of the balanced matrix (the maximum of the sum of absolute values of elements in any of the matrix columns).
rconde
[out] Vector of reciprocal condition numbers for each eigenvalue; it is computed if the 'sense' parameter is set to 'E' or 'B'.
rcondv
[out] Vector of reciprocal condition numbers for each eigenvector; it is computed if the 'sense' parameter is set to 'V' or 'B.
Return Value
Return true if successful, otherwise false in case of an error.
Note
Input matrix balancing depends on the value of the 'balance' parameter.
An enumeration defining the need to compute eigenvectors.
ID |
Description |
---|---|
EIGBALANCE_N |
Do not diagonally scale or permute |
EIGBALANCE_P |
Perform permutations to make the matrix more nearly upper triangular. Do not diagonally scale |
EIGBALANCE_S |
Diagonally scale the matrix. Do not permute |
EIGBALANCE_B |
Both diagonally scale and permute |
ENUM_EIG_VECTORS
An enumeration defining the need to compute eigenvectors.
ID |
Description |
---|---|
EIGVECTORS_N |
Only eigenvalues are computed, without vectors. |
EIGVECTORS_L |
Only left eigenvectors are computed. |
EIGVECTORS_R |
Only right eigenvectors are computed. |
EIGVECTORS_LR |
Left and right eigenvectors are computed, eigenvalues are always computed. |
An enumeration defining the need to compute eigenvectors.
ID |
Description |
---|---|
EIGSENSE_N |
None of reciprocal condition numbers are computed |
EIGSENSE_E |
Computed for eigenvalues only |
EIGSENSE_V |
Computed for right eigenvectors only |
EIGSENSE_B |
Computed for eigenvalues and right eigenvectors |