ZLANV2(l) ) ZLANV2(l)NAME
ZLANV2 - compute the Schur factorization of a complex 2-by-2 nonhermi‐
tian matrix in standard form
SYNOPSIS
SUBROUTINE ZLANV2( A, B, C, D, RT1, RT2, CS, SN )
DOUBLE PRECISION CS
COMPLEX*16 A, B, C, D, RT1, RT2, SN
PURPOSE
ZLANV2 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*16
B (input/output) COMPLEX*16 C (input/output) COM‐
PLEX*16 D (input/output) COMPLEX*16 On entry, the ele‐
ments of the input matrix. On exit, they are overwritten by
the elements of the standardised Schur form.
RT1 (output) COMPLEX*16
RT2 (output) COMPLEX*16 The two eigenvalues.
CS (output) DOUBLE PRECISION
SN (output) COMPLEX*16 Parameters of the rotation matrix.
FURTHER DETAILS
Implemented by Mark R. Fahey, May 28, 1999
ScaLAPACK version 1.7 13 August 2001 ZLANV2(l)
