diff options
Diffstat (limited to 'SRC/zlaqr3.f')
| -rw-r--r-- | SRC/zlaqr3.f | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/SRC/zlaqr3.f b/SRC/zlaqr3.f index 2a10ac9f..79a1fff4 100644 --- a/SRC/zlaqr3.f +++ b/SRC/zlaqr3.f @@ -16,10 +16,12 @@ $ WORK( * ), WV( LDWV, * ), Z( LDZ, * ) * .. * -* ****************************************************************** +* Purpose +* ======= +* * Aggressive early deflation: * -* This subroutine accepts as input an upper Hessenberg matrix +* ZLAQR3 accepts as input an upper Hessenberg matrix * H and performs an unitary similarity transformation * designed to detect and deflate fully converged eigenvalues from * a trailing principal submatrix. On output H has been over- @@ -28,7 +30,10 @@ * hoped that the final version of H has many zero subdiagonal * entries. * -* ****************************************************************** +* +* Arguments +* ========= +* * WANTT (input) LOGICAL * If .TRUE., then the Hessenberg matrix H is fully updated * so that the triangular Schur factor may be @@ -73,6 +78,7 @@ * subroutine. N .LE. LDH * * ILOZ (input) INTEGER +* * IHIZ (input) INTEGER * Specify the rows of Z to which transformations must be * applied if WANTZ is .TRUE.. 1 .LE. ILOZ .LE. IHIZ .LE. N. @@ -143,12 +149,15 @@ * in WORK(1). No error message related to LWORK is issued * by XERBLA. Neither H nor Z are accessed. * -* ================================================================ +* Further Details +* =============== +* * Based on contributions by * Karen Braman and Ralph Byers, Department of Mathematics, * University of Kansas, USA * -* ================================================================ +* ================================================================ +* * .. Parameters .. COMPLEX*16 ZERO, ONE PARAMETER ( ZERO = ( 0.0d0, 0.0d0 ), |