diff options
Diffstat (limited to 'SRC/dlarfb.f')
| -rw-r--r-- | SRC/dlarfb.f | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/SRC/dlarfb.f b/SRC/dlarfb.f index ca7ab0d8..3c5cb4eb 100644 --- a/SRC/dlarfb.f +++ b/SRC/dlarfb.f @@ -59,7 +59,7 @@ * (LDV,K) if STOREV = 'C' * (LDV,M) if STOREV = 'R' and SIDE = 'L' * (LDV,N) if STOREV = 'R' and SIDE = 'R' -* The matrix V. See further details. +* The matrix V. See Further Details. * * LDV (input) INTEGER * The leading dimension of the array V. @@ -88,6 +88,31 @@ * If SIDE = 'L', LDWORK >= max(1,N); * if SIDE = 'R', LDWORK >= max(1,M). * +* Further Details +* =============== +* +* The shape of the matrix V and the storage of the vectors which define +* the H(i) is best illustrated by the following example with n = 5 and +* k = 3. The elements equal to 1 are not stored; the corresponding +* array elements are modified but restored on exit. The rest of the +* array is not used. +* +* DIRECT = 'F' and STOREV = 'C': DIRECT = 'F' and STOREV = 'R': +* +* V = ( 1 ) V = ( 1 v1 v1 v1 v1 ) +* ( v1 1 ) ( 1 v2 v2 v2 ) +* ( v1 v2 1 ) ( 1 v3 v3 ) +* ( v1 v2 v3 ) +* ( v1 v2 v3 ) +* +* DIRECT = 'B' and STOREV = 'C': DIRECT = 'B' and STOREV = 'R': +* +* V = ( v1 v2 v3 ) V = ( v1 v1 1 ) +* ( v1 v2 v3 ) ( v2 v2 v2 1 ) +* ( 1 v2 v3 ) ( v3 v3 v3 v3 1 ) +* ( 1 v3 ) +* ( 1 ) +* * ===================================================================== * * .. Parameters .. |