Provided by: liblapack-doc_3.3.1-1_all bug

NAME

       LAPACK-3  -  computes  the  Schur  factorization  of  a real 2-by-2 nonsymmetric matrix in
       standard form

SYNOPSIS

       SUBROUTINE SLANV2( A, B, C, D, RT1R, RT1I, RT2R, RT2I, CS, SN )

           REAL           A, B, C, CS, D, RT1I, RT1R, RT2I, RT2R, SN

PURPOSE

       SLANV2 computes the Schur factorization of a real 2-by-2 nonsymmetric matrix  in  standard
       form:
             [ A  B ] = [ CS -SN ] [ AA  BB ] [ CS  SN ]
             [ C  D ]   [ SN  CS ] [ CC  DD ] [-SN  CS ]
        where either
        1) CC = 0 so that AA and DD are real eigenvalues of the matrix, or
        2) AA = DD and BB*CC < 0, so that AA + or - sqrt(BB*CC) are complex
        conjugate eigenvalues.

ARGUMENTS

        A       (input/output) REAL
                B       (input/output) REAL
                C       (input/output) REAL
                D       (input/output) REAL
                On entry, the elements of the input matrix.
                On exit, they are overwritten by the elements of the
                standardised Schur form.

        RT1R    (output) REAL
                RT1I    (output) REAL
                RT2R    (output) REAL
                RT2I    (output) REAL
                The real and imaginary parts of the eigenvalues. If the
                eigenvalues are a complex conjugate pair, RT1I > 0.

        CS      (output) REAL
                SN      (output) REAL
                Parameters of the rotation matrix.

FURTHER DETAILS

        Modified by V. Sima, Research Institute for Informatics, Bucharest,
        Romania, to reduce the risk of cancellation errors,
        when computing real eigenvalues, and to ensure, if possible, that
        abs(RT1R) >= abs(RT2R).

 LAPACK auxiliary routine (version 3.2.2)   April 2011                            SLANV2(3lapack)