diff options
Diffstat (limited to 'SRC/dlaqr3.f')
| -rw-r--r-- | SRC/dlaqr3.f | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/SRC/dlaqr3.f b/SRC/dlaqr3.f index d952eea8..a0a0c475 100644 --- a/SRC/dlaqr3.f +++ b/SRC/dlaqr3.f @@ -17,10 +17,12 @@ $ Z( LDZ, * ) * .. * -* ****************************************************************** +* Purpose +* ======= +* * Aggressive early deflation: * -* This subroutine accepts as input an upper Hessenberg matrix +* DLAQR3 accepts as input an upper Hessenberg matrix * H and performs an orthogonal similarity transformation * designed to detect and deflate fully converged eigenvalues from * a trailing principal submatrix. On output H has been over- @@ -29,7 +31,9 @@ * 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 quasi-triangular Schur factor may be @@ -74,6 +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. @@ -98,6 +103,7 @@ * subroutine. * * SR (output) DOUBLE PRECISION array, dimension (KBOT) +* * SI (output) DOUBLE PRECISION array, dimension (KBOT) * On output, the real and imaginary parts of approximate * eigenvalues that may be used for shifts are stored in @@ -148,12 +154,14 @@ * 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 .. DOUBLE PRECISION ZERO, ONE PARAMETER ( ZERO = 0.0d0, ONE = 1.0d0 ) |