_RGG(3F)_RGG(3F)NAME
RGG, SRGG - EISPACK routine. This subroutine calls the recommended
sequence of subroutines from the eigensystem subroutine package (EISPACK)
to find the eigenvalues and eigenvectors (if desired) for the REAL
GENERAL GENERALIZED eigenproblem Ax = (LAMBDA)Bx.
SYNOPSYS
subroutine rgg(nm, n, a, b, alfr, alfi, beta, matz, z, ierr)
integer nm, n, matz, ierr
double precision a(nm,n),b(nm,n),alfr(n),alfi(n),beta(n),z(nm,n)
subroutine srgg(nm, n, a, b, alfr, alfi, beta, matz, z, ierr)
integer nm, n, matz, ierr
real a(nm,n),b(nm,n),alfr(n),alfi(n),beta(n),z(nm,n)
DESCRIPTION
On Input
NM must be set to the row dimension of the two-dimensional array
parameters as declared in the calling program dimension statement.
N is the order of the matrices A and B.
A contains a real general matrix.
B contains a real general matrix.
MATZ is an integer variable set equal to zero if only eigenvalues are
desired. Otherwise it is set to any non-zero integer for both
eigenvalues and eigenvectors. On Output
ALFR and ALFI contain the real and imaginary parts, respectively, of
the numerators of the eigenvalues.
BETA contains the denominators of the eigenvalues, which are thus given
by the ratios (ALFR+I*ALFI)/BETA. Complex conjugate pairs of
eigenvalues appear consecutively with the eigenvalue having the positive
imaginary part first.
Z contains the real and imaginary parts of the eigenvectors if MATZ is
not zero. If the J-th eigenvalue is real, the J-th column of Z
contains its eigenvector. If the J-th eigenvalue is complex with
positive imaginary part, the J-th and (J+1)-th columns of Z contain the
real and imaginary parts of its eigenvector. The conjugate of this
vector is the eigenvector for the conjugate eigenvalue.
IERR is an integer output variable set equal to an error completion code
described in section 2B of the documentation. The normal completion code
is zero. Questions and comments should be directed to B. S. Garbow,
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_RGG(3F)_RGG(3F)
APPLIED MATHEMATICS DIVISION, ARGONNE NATIONAL LABORATORY
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