slarfb (l)  Linux Man Pages
slarfb: applies a real block reflector H or its transpose Haq to a real m by n matrix C, from either the left or the right
Command to display slarfb
manual in Linux: $ man l slarfb
NAME
SLARFB  applies a real block reflector H or its transpose Haq to a real m by n matrix C, from either the left or the right
SYNOPSIS
 SUBROUTINE SLARFB(

SIDE, TRANS, DIRECT, STOREV, M, N, K, V, LDV,
T, LDT, C, LDC, WORK, LDWORK )

IMPLICIT
NONE

CHARACTER
DIRECT, SIDE, STOREV, TRANS

INTEGER
K, LDC, LDT, LDV, LDWORK, M, N

REAL
C( LDC, * ), T( LDT, * ), V( LDV, * ),
WORK( LDWORK, * )
PURPOSE
SLARFB applies a real block reflector H or its transpose Haq to a
real m by n matrix C, from either the left or the right.
ARGUMENTS
 SIDE (input) CHARACTER*1

= aqLaq: apply H or Haq from the Left
= aqRaq: apply H or Haq from the Right
 TRANS (input) CHARACTER*1

= aqNaq: apply H (No transpose)
= aqTaq: apply Haq (Transpose)
 DIRECT (input) CHARACTER*1

Indicates how H is formed from a product of elementary
reflectors
= aqFaq: H = H(1) H(2) . . . H(k) (Forward)
= aqBaq: H = H(k) . . . H(2) H(1) (Backward)
 STOREV (input) CHARACTER*1

Indicates how the vectors which define the elementary
reflectors are stored:
= aqCaq: Columnwise
= aqRaq: Rowwise
 M (input) INTEGER

The number of rows of the matrix C.
 N (input) INTEGER

The number of columns of the matrix C.
 K (input) INTEGER

The order of the matrix T (= the number of elementary
reflectors whose product defines the block reflector).
 V (input) REAL array, dimension

(LDV,K) if STOREV = aqCaq
(LDV,M) if STOREV = aqRaq and SIDE = aqLaq
(LDV,N) if STOREV = aqRaq and SIDE = aqRaq
The matrix V. See further details.
 LDV (input) INTEGER

The leading dimension of the array V.
If STOREV = aqCaq and SIDE = aqLaq, LDV >= max(1,M);
if STOREV = aqCaq and SIDE = aqRaq, LDV >= max(1,N);
if STOREV = aqRaq, LDV >= K.
 T (input) REAL array, dimension (LDT,K)

The triangular k by k matrix T in the representation of the
block reflector.
 LDT (input) INTEGER

The leading dimension of the array T. LDT >= K.
 C (input/output) REAL array, dimension (LDC,N)

On entry, the m by n matrix C.
On exit, C is overwritten by H*C or Haq*C or C*H or C*Haq.
 LDC (input) INTEGER

The leading dimension of the array C. LDA >= max(1,M).
 WORK (workspace) REAL array, dimension (LDWORK,K)

 LDWORK (input) INTEGER

The leading dimension of the array WORK.
If SIDE = aqLaq, LDWORK >= max(1,N);
if SIDE = aqRaq, LDWORK >= max(1,M).
Pages related to slarfb
 slarfb (3)
 slarf (l)  applies a real elementary reflector H to a real m by n matrix C, from either the left or the right
 slarfg (l)  generates a real elementary reflector H of order n, such that H * ( alpha ) = ( beta ), Haq * H = I
 slarfp (l)  generates a real elementary reflector H of order n, such that H * ( alpha ) = ( beta ), Haq * H = I
 slarft (l)  forms the triangular factor T of a real block reflector H of order n, which is defined as a product of k elementary reflectors
 slarfx (l)  applies a real elementary reflector H to a real m by n matrix C, from either the left or the right
 slar1v (l)  computes the (scaled) rth column of the inverse of the sumbmatrix in rows B1 through BN of the tridiagonal matrix L D L^T  sigma I
 slar2v (l)  applies a vector of real plane rotations from both sides to a sequence of 2by2 real symmetric matrices, defined by the elements of the vectors x, y and z
 slargv (l)  generates a vector of real plane rotations, determined by elements of the real vectors x and y
 slarnv (l)  returns a vector of n random real numbers from a uniform or normal distribution