ML_DGEEV – Computes the eigenvalues and, optionally, the left and/or right eigenvectors

Block SymbolLicensing group: MATRIX

Function Description
The output references yA, yWR, yWI, yVL, yVR and yWORK are always set to the corresponding input references uA, uWR, uWI, uVL, uVR and uWORK. If HLD = on then nothing is computed otherwise the LAPACK function DGEEV is called internally:

DGEEV(sJOBVL, sJOBVR, N, uA, LDA, uWR, uWI, uVL, LDVL, uVR, LDVR,
uWORK, LWORK, info);

where parameters of DGEEV are set in the following way:

If $JOBVL = on$ then the string sJOBVL is set to "V" else it is set to "N".
If $JOBVR = on$ then the string sJOBVR is set to "V" else it is set to "N".
N is number of columns of the matrix referenced by uA.
LDA, LDVL and LDVR are leading dimensions of the matrices referenced by uA, uVL and uVR.
LWORK is number of elements of the vector referenced by uWORK.
info is return code from the function DGEEV.

The error flag E is set to on if:

the reference uA or uWR or uWI or uVL or uVR or uWORK is not defined (i.e. input uA or uWR or uWI or uVL or uVR or uWORK is not connected),
the matrix referenced by uA is not square,
number of elements of vectors referenced by uWR or uWI is less than N,
number of columns of matrices referenced by uVL or uVR is not equal to N,
the call of the function DGEEV returns error using the function XERBLA, see the return code info and system log.

See LAPACK documentation [8] for more details.

Inputs

uA	Input reference to matrix A	Reference
uWR	Input reference to vector of real parts of eigenvalues	Reference
uWI	Input reference to vector of imaginary parts of eigenvalues	Reference
uVL	Input reference to matrix of left eigenvectors	Reference
uVR	Input reference to matrix of right eigenvectors	Reference
uWORK	Input reference to working vector WORK	Reference
JOBVL	If true then left eigenvectors are computed	Bool
JOBVR	If true then right eigenvectors are computed	Bool
HLD	Hold	Bool

Outputs

yA	Output reference to matrix A	Reference
yWR	Output reference to vector of real parts of eigenvalues	Reference
yWI	Output reference to vector of imaginary parts of eigenvalues	Reference
yVL	Output reference to VL	Reference
yVR	Output reference to VR	Reference
yWORK	Output reference to working vector WORK	Reference
E	Error indicator	Bool
info	LAPACK function result info. If info = -i, the i=th argument had an illegal value	Long (I32)

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