CLANV2(3)     ScaLAPACK routine of NEC Numeric Library Collection    CLANV2(3)



NAME
       CLANV2  - compute the Schur factorization of a complex 2-by-2 nonhermi-
       tian matrix in standard form

SYNOPSIS
       SUBROUTINE CLANV2( A, B, C, D, RT1, RT2, CS, SN )

           REAL           CS

           COMPLEX        A, B, C, D, RT1, RT2, SN

PURPOSE
       CLANV2 computes the Schur factorization of a complex  2-by-2  nonhermi-
       tian matrix in standard form:
            [ A  B ] = [ CS -SN ] [ AA  BB ] [ CS  SN ]
            [ C  D ]   [ SN  CS ] [  0  DD ] [-SN  CS ]


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

       RT1     (output) COMPLEX
               RT2     (output) COMPLEX The two eigenvalues.

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

FURTHER DETAILS
       Implemented by Mark R. Fahey, May 28, 1999




ScaLAPACK routine               31 October 2017                      CLANV2(3)