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subroutine rg(nm,n,a,wr,wi,matz,z,iv1,fv1,ierr)
c
integer n,nm,is1,is2,ierr,matz
double precision a(nm,n),wr(n),wi(n),z(nm,n),fv1(n)
integer iv1(n)
c
c this subroutine calls the recommended sequence of
c subroutines from the eigensystem subroutine package (eispack)
c to find the eigenvalues and eigenvectors (if desired)
c of a real general matrix.
c
c on input
c
c nm must be set to the row dimension of the two-dimensional
c array parameters as declared in the calling program
c dimension statement.
c
c n is the order of the matrix a.
c
c a contains the real general matrix.
c
c matz is an integer variable set equal to zero if
c only eigenvalues are desired. otherwise it is set to
c any non-zero integer for both eigenvalues and eigenvectors.
c
c on output
c
c wr and wi contain the real and imaginary parts,
c respectively, of the eigenvalues. complex conjugate
c pairs of eigenvalues appear consecutively with the
c eigenvalue having the positive imaginary part first.
c
c z contains the real and imaginary parts of the eigenvectors
c if matz is not zero. if the j-th eigenvalue is real, the
c j-th column of z contains its eigenvector. if the j-th
c eigenvalue is complex with positive imaginary part, the
c j-th and (j+1)-th columns of z contain the real and
c imaginary parts of its eigenvector. the conjugate of this
c vector is the eigenvector for the conjugate eigenvalue.
c
c ierr is an integer output variable set equal to an error
c completion code described in the documentation for hqr
c and hqr2. the normal completion code is zero.
c
c iv1 and fv1 are temporary storage arrays.
c
c questions and comments should be directed to burton s. garbow,
c mathematics and computer science div, argonne national laboratory
c
c this version dated august 1983.
c
c ------------------------------------------------------------------
c
if (n .le. nm) go to 10
ierr = 10 * n
go to 50
c
10 call balanc(nm,n,a,is1,is2,fv1)
call elmhes(nm,n,is1,is2,a,iv1)
if (matz .ne. 0) go to 20
c .......... find eigenvalues only ..........
call hqr(nm,n,is1,is2,a,wr,wi,ierr)
go to 50
c .......... find both eigenvalues and eigenvectors ..........
20 call eltran(nm,n,is1,is2,a,iv1,z)
call hqr2(nm,n,is1,is2,a,wr,wi,z,ierr)
if (ierr .ne. 0) go to 50
call balbak(nm,n,is1,is2,fv1,n,z)
50 return
end
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