/* -- translated by f2c (version 20100827).
You must link the resulting object file with libf2c:
on Microsoft Windows system, link with libf2c.lib;
on Linux or Unix systems, link with .../path/to/libf2c.a -lm
or, if you install libf2c.a in a standard place, with -lf2c -lm
-- in that order, at the end of the command line, as in
cc *.o -lf2c -lm
Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
http://www.netlib.org/f2c/libf2c.zip
*/
#include "f2c.h"
/* Table of constant values */
static integer c__1 = 1;
static doublereal c_b14 = 1.;
static doublereal c_b25 = -1.;
/* > \brief \b DLARFB applies a block reflector or its transpose to a general rectangular matrix.
=========== DOCUMENTATION ===========
Online html documentation available at
http://www.netlib.org/lapack/explore-html/
> \htmlonly
> Download DLARFB + dependencies
> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlarfb.
f">
> [TGZ]</a>
> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlarfb.
f">
> [ZIP]</a>
> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlarfb.
f">
> [TXT]</a>
> \endhtmlonly
Definition:
===========
SUBROUTINE DLARFB( SIDE, TRANS, DIRECT, STOREV, M, N, K, V, LDV,
T, LDT, C, LDC, WORK, LDWORK )
CHARACTER DIRECT, SIDE, STOREV, TRANS
INTEGER K, LDC, LDT, LDV, LDWORK, M, N
DOUBLE PRECISION C( LDC, * ), T( LDT, * ), V( LDV, * ),
$ WORK( LDWORK, * )
> \par Purpose:
=============
>
> \verbatim
>
> DLARFB applies a real block reflector H or its transpose H**T to a
> real m by n matrix C, from either the left or the right.
> \endverbatim
Arguments:
==========
> \param[in] SIDE
> \verbatim
> SIDE is CHARACTER*1
> = 'L': apply H or H**T from the Left
> = 'R': apply H or H**T from the Right
> \endverbatim
>
> \param[in] TRANS
> \verbatim
> TRANS is CHARACTER*1
> = 'N': apply H (No transpose)
> = 'T': apply H**T (Transpose)
> \endverbatim
>
> \param[in] DIRECT
> \verbatim
> DIRECT is CHARACTER*1
> Indicates how H is formed from a product of elementary
> reflectors
> = 'F': H = H(1) H(2) . . . H(k) (Forward)
> = 'B': H = H(k) . . . H(2) H(1) (Backward)
> \endverbatim
>
> \param[in] STOREV
> \verbatim
> STOREV is CHARACTER*1
> Indicates how the vectors which define the elementary
> reflectors are stored:
> = 'C': Columnwise
> = 'R': Rowwise
> \endverbatim
>
> \param[in] M
> \verbatim
> M is INTEGER
> The number of rows of the matrix C.
> \endverbatim
>
> \param[in] N
> \verbatim
> N is INTEGER
> The number of columns of the matrix C.
> \endverbatim
>
> \param[in] K
> \verbatim
> K is INTEGER
> The order of the matrix T (= the number of elementary
> reflectors whose product defines the block reflector).
> \endverbatim
>
> \param[in] V
> \verbatim
> V is DOUBLE PRECISION array, dimension
> (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.
> \endverbatim
>
> \param[in] LDV
> \verbatim
> LDV is INTEGER
> The leading dimension of the array V.
> If STOREV = 'C' and SIDE = 'L', LDV >= max(1,M);
> if STOREV = 'C' and SIDE = 'R', LDV >= max(1,N);
> if STOREV = 'R', LDV >= K.
> \endverbatim
>
> \param[in] T
> \verbatim
> T is DOUBLE PRECISION array, dimension (LDT,K)
> The triangular k by k matrix T in the representation of the
> block reflector.
> \endverbatim
>
> \param[in] LDT
> \verbatim
> LDT is INTEGER
> The leading dimension of the array T. LDT >= K.
> \endverbatim
>
> \param[in,out] C
> \verbatim
> C is DOUBLE PRECISION array, dimension (LDC,N)
> On entry, the m by n matrix C.
> On exit, C is overwritten by H*C or H**T*C or C*H or C*H**T.
> \endverbatim
>
> \param[in] LDC
> \verbatim
> LDC is INTEGER
> The leading dimension of the array C. LDC >= max(1,M).
> \endverbatim
>
> \param[out] WORK
> \verbatim
> WORK is DOUBLE PRECISION array, dimension (LDWORK,K)
> \endverbatim
>
> \param[in] LDWORK
> \verbatim
> LDWORK is INTEGER
> The leading dimension of the array WORK.
> If SIDE = 'L', LDWORK >= max(1,N);
> if SIDE = 'R', LDWORK >= max(1,M).
> \endverbatim
Authors:
========
> \author Univ. of Tennessee
> \author Univ. of California Berkeley
> \author Univ. of Colorado Denver
> \author NAG Ltd.
> \date June 2013
> \ingroup doubleOTHERauxiliary
> \par Further Details:
=====================
>
> \verbatim
>
> 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 )
> \endverbatim
>
=====================================================================
Subroutine */ int igraphdlarfb_(char *side, char *trans, char *direct, char *
storev, integer *m, integer *n, integer *k, doublereal *v, integer *
ldv, doublereal *t, integer *ldt, doublereal *c__, integer *ldc,
doublereal *work, integer *ldwork)
{
/* System generated locals */
integer c_dim1, c_offset, t_dim1, t_offset, v_dim1, v_offset, work_dim1,
work_offset, i__1, i__2;
/* Local variables */
integer i__, j;
extern /* Subroutine */ int igraphdgemm_(char *, char *, integer *, integer *,
integer *, doublereal *, doublereal *, integer *, doublereal *,
integer *, doublereal *, doublereal *, integer *);
extern logical igraphlsame_(char *, char *);
extern /* Subroutine */ int igraphdcopy_(integer *, doublereal *, integer *,
doublereal *, integer *), igraphdtrmm_(char *, char *, char *, char *,
integer *, integer *, doublereal *, doublereal *, integer *,
doublereal *, integer *);
char transt[1];
/* -- LAPACK auxiliary routine (version 3.5.0) --
-- LAPACK is a software package provided by Univ. of Tennessee, --
-- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
June 2013
=====================================================================
Quick return if possible
Parameter adjustments */
v_dim1 = *ldv;
v_offset = 1 + v_dim1;
v -= v_offset;
t_dim1 = *ldt;
t_offset = 1 + t_dim1;
t -= t_offset;
c_dim1 = *ldc;
c_offset = 1 + c_dim1;
c__ -= c_offset;
work_dim1 = *ldwork;
work_offset = 1 + work_dim1;
work -= work_offset;
/* Function Body */
if (*m <= 0 || *n <= 0) {
return 0;
}
if (igraphlsame_(trans, "N")) {
*(unsigned char *)transt = 'T';
} else {
*(unsigned char *)transt = 'N';
}
if (igraphlsame_(storev, "C")) {
if (igraphlsame_(direct, "F")) {
/* Let V = ( V1 ) (first K rows)
( V2 )
where V1 is unit lower triangular. */
if (igraphlsame_(side, "L")) {
/* Form H * C or H**T * C where C = ( C1 )
( C2 )
W := C**T * V = (C1**T * V1 + C2**T * V2) (stored in WORK)
W := C1**T */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
igraphdcopy_(n, &c__[j + c_dim1], ldc, &work[j * work_dim1 + 1],
&c__1);
/* L10: */
}
/* W := W * V1 */
igraphdtrmm_("Right", "Lower", "No transpose", "Unit", n, k, &c_b14,
&v[v_offset], ldv, &work[work_offset], ldwork);
if (*m > *k) {
/* W := W + C2**T * V2 */
i__1 = *m - *k;
igraphdgemm_("Transpose", "No transpose", n, k, &i__1, &c_b14, &
c__[*k + 1 + c_dim1], ldc, &v[*k + 1 + v_dim1],
ldv, &c_b14, &work[work_offset], ldwork);
}
/* W := W * T**T or W * T */
igraphdtrmm_("Right", "Upper", transt, "Non-unit", n, k, &c_b14, &t[
t_offset], ldt, &work[work_offset], ldwork);
/* C := C - V * W**T */
if (*m > *k) {
/* C2 := C2 - V2 * W**T */
i__1 = *m - *k;
igraphdgemm_("No transpose", "Transpose", &i__1, n, k, &c_b25, &
v[*k + 1 + v_dim1], ldv, &work[work_offset],
ldwork, &c_b14, &c__[*k + 1 + c_dim1], ldc);
}
/* W := W * V1**T */
igraphdtrmm_("Right", "Lower", "Transpose", "Unit", n, k, &c_b14, &
v[v_offset], ldv, &work[work_offset], ldwork);
/* C1 := C1 - W**T */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
i__2 = *n;
for (i__ = 1; i__ <= i__2; ++i__) {
c__[j + i__ * c_dim1] -= work[i__ + j * work_dim1];
/* L20: */
}
/* L30: */
}
} else if (igraphlsame_(side, "R")) {
/* Form C * H or C * H**T where C = ( C1 C2 )
W := C * V = (C1*V1 + C2*V2) (stored in WORK)
W := C1 */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
igraphdcopy_(m, &c__[j * c_dim1 + 1], &c__1, &work[j *
work_dim1 + 1], &c__1);
/* L40: */
}
/* W := W * V1 */
igraphdtrmm_("Right", "Lower", "No transpose", "Unit", m, k, &c_b14,
&v[v_offset], ldv, &work[work_offset], ldwork);
if (*n > *k) {
/* W := W + C2 * V2 */
i__1 = *n - *k;
igraphdgemm_("No transpose", "No transpose", m, k, &i__1, &
c_b14, &c__[(*k + 1) * c_dim1 + 1], ldc, &v[*k +
1 + v_dim1], ldv, &c_b14, &work[work_offset],
ldwork);
}
/* W := W * T or W * T**T */
igraphdtrmm_("Right", "Upper", trans, "Non-unit", m, k, &c_b14, &t[
t_offset], ldt, &work[work_offset], ldwork);
/* C := C - W * V**T */
if (*n > *k) {
/* C2 := C2 - W * V2**T */
i__1 = *n - *k;
igraphdgemm_("No transpose", "Transpose", m, &i__1, k, &c_b25, &
work[work_offset], ldwork, &v[*k + 1 + v_dim1],
ldv, &c_b14, &c__[(*k + 1) * c_dim1 + 1], ldc);
}
/* W := W * V1**T */
igraphdtrmm_("Right", "Lower", "Transpose", "Unit", m, k, &c_b14, &
v[v_offset], ldv, &work[work_offset], ldwork);
/* C1 := C1 - W */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
i__2 = *m;
for (i__ = 1; i__ <= i__2; ++i__) {
c__[i__ + j * c_dim1] -= work[i__ + j * work_dim1];
/* L50: */
}
/* L60: */
}
}
} else {
/* Let V = ( V1 )
( V2 ) (last K rows)
where V2 is unit upper triangular. */
if (igraphlsame_(side, "L")) {
/* Form H * C or H**T * C where C = ( C1 )
( C2 )
W := C**T * V = (C1**T * V1 + C2**T * V2) (stored in WORK)
W := C2**T */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
igraphdcopy_(n, &c__[*m - *k + j + c_dim1], ldc, &work[j *
work_dim1 + 1], &c__1);
/* L70: */
}
/* W := W * V2 */
igraphdtrmm_("Right", "Upper", "No transpose", "Unit", n, k, &c_b14,
&v[*m - *k + 1 + v_dim1], ldv, &work[work_offset],
ldwork);
if (*m > *k) {
/* W := W + C1**T * V1 */
i__1 = *m - *k;
igraphdgemm_("Transpose", "No transpose", n, k, &i__1, &c_b14, &
c__[c_offset], ldc, &v[v_offset], ldv, &c_b14, &
work[work_offset], ldwork);
}
/* W := W * T**T or W * T */
igraphdtrmm_("Right", "Lower", transt, "Non-unit", n, k, &c_b14, &t[
t_offset], ldt, &work[work_offset], ldwork);
/* C := C - V * W**T */
if (*m > *k) {
/* C1 := C1 - V1 * W**T */
i__1 = *m - *k;
igraphdgemm_("No transpose", "Transpose", &i__1, n, k, &c_b25, &
v[v_offset], ldv, &work[work_offset], ldwork, &
c_b14, &c__[c_offset], ldc)
;
}
/* W := W * V2**T */
igraphdtrmm_("Right", "Upper", "Transpose", "Unit", n, k, &c_b14, &
v[*m - *k + 1 + v_dim1], ldv, &work[work_offset],
ldwork);
/* C2 := C2 - W**T */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
i__2 = *n;
for (i__ = 1; i__ <= i__2; ++i__) {
c__[*m - *k + j + i__ * c_dim1] -= work[i__ + j *
work_dim1];
/* L80: */
}
/* L90: */
}
} else if (igraphlsame_(side, "R")) {
/* Form C * H or C * H**T where C = ( C1 C2 )
W := C * V = (C1*V1 + C2*V2) (stored in WORK)
W := C2 */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
igraphdcopy_(m, &c__[(*n - *k + j) * c_dim1 + 1], &c__1, &work[
j * work_dim1 + 1], &c__1);
/* L100: */
}
/* W := W * V2 */
igraphdtrmm_("Right", "Upper", "No transpose", "Unit", m, k, &c_b14,
&v[*n - *k + 1 + v_dim1], ldv, &work[work_offset],
ldwork);
if (*n > *k) {
/* W := W + C1 * V1 */
i__1 = *n - *k;
igraphdgemm_("No transpose", "No transpose", m, k, &i__1, &
c_b14, &c__[c_offset], ldc, &v[v_offset], ldv, &
c_b14, &work[work_offset], ldwork);
}
/* W := W * T or W * T**T */
igraphdtrmm_("Right", "Lower", trans, "Non-unit", m, k, &c_b14, &t[
t_offset], ldt, &work[work_offset], ldwork);
/* C := C - W * V**T */
if (*n > *k) {
/* C1 := C1 - W * V1**T */
i__1 = *n - *k;
igraphdgemm_("No transpose", "Transpose", m, &i__1, k, &c_b25, &
work[work_offset], ldwork, &v[v_offset], ldv, &
c_b14, &c__[c_offset], ldc)
;
}
/* W := W * V2**T */
igraphdtrmm_("Right", "Upper", "Transpose", "Unit", m, k, &c_b14, &
v[*n - *k + 1 + v_dim1], ldv, &work[work_offset],
ldwork);
/* C2 := C2 - W */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
i__2 = *m;
for (i__ = 1; i__ <= i__2; ++i__) {
c__[i__ + (*n - *k + j) * c_dim1] -= work[i__ + j *
work_dim1];
/* L110: */
}
/* L120: */
}
}
}
} else if (igraphlsame_(storev, "R")) {
if (igraphlsame_(direct, "F")) {
/* Let V = ( V1 V2 ) (V1: first K columns)
where V1 is unit upper triangular. */
if (igraphlsame_(side, "L")) {
/* Form H * C or H**T * C where C = ( C1 )
( C2 )
W := C**T * V**T = (C1**T * V1**T + C2**T * V2**T) (stored in WORK)
W := C1**T */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
igraphdcopy_(n, &c__[j + c_dim1], ldc, &work[j * work_dim1 + 1],
&c__1);
/* L130: */
}
/* W := W * V1**T */
igraphdtrmm_("Right", "Upper", "Transpose", "Unit", n, k, &c_b14, &
v[v_offset], ldv, &work[work_offset], ldwork);
if (*m > *k) {
/* W := W + C2**T * V2**T */
i__1 = *m - *k;
igraphdgemm_("Transpose", "Transpose", n, k, &i__1, &c_b14, &
c__[*k + 1 + c_dim1], ldc, &v[(*k + 1) * v_dim1 +
1], ldv, &c_b14, &work[work_offset], ldwork);
}
/* W := W * T**T or W * T */
igraphdtrmm_("Right", "Upper", transt, "Non-unit", n, k, &c_b14, &t[
t_offset], ldt, &work[work_offset], ldwork);
/* C := C - V**T * W**T */
if (*m > *k) {
/* C2 := C2 - V2**T * W**T */
i__1 = *m - *k;
igraphdgemm_("Transpose", "Transpose", &i__1, n, k, &c_b25, &v[(
*k + 1) * v_dim1 + 1], ldv, &work[work_offset],
ldwork, &c_b14, &c__[*k + 1 + c_dim1], ldc);
}
/* W := W * V1 */
igraphdtrmm_("Right", "Upper", "No transpose", "Unit", n, k, &c_b14,
&v[v_offset], ldv, &work[work_offset], ldwork);
/* C1 := C1 - W**T */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
i__2 = *n;
for (i__ = 1; i__ <= i__2; ++i__) {
c__[j + i__ * c_dim1] -= work[i__ + j * work_dim1];
/* L140: */
}
/* L150: */
}
} else if (igraphlsame_(side, "R")) {
/* Form C * H or C * H**T where C = ( C1 C2 )
W := C * V**T = (C1*V1**T + C2*V2**T) (stored in WORK)
W := C1 */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
igraphdcopy_(m, &c__[j * c_dim1 + 1], &c__1, &work[j *
work_dim1 + 1], &c__1);
/* L160: */
}
/* W := W * V1**T */
igraphdtrmm_("Right", "Upper", "Transpose", "Unit", m, k, &c_b14, &
v[v_offset], ldv, &work[work_offset], ldwork);
if (*n > *k) {
/* W := W + C2 * V2**T */
i__1 = *n - *k;
igraphdgemm_("No transpose", "Transpose", m, k, &i__1, &c_b14, &
c__[(*k + 1) * c_dim1 + 1], ldc, &v[(*k + 1) *
v_dim1 + 1], ldv, &c_b14, &work[work_offset],
ldwork);
}
/* W := W * T or W * T**T */
igraphdtrmm_("Right", "Upper", trans, "Non-unit", m, k, &c_b14, &t[
t_offset], ldt, &work[work_offset], ldwork);
/* C := C - W * V */
if (*n > *k) {
/* C2 := C2 - W * V2 */
i__1 = *n - *k;
igraphdgemm_("No transpose", "No transpose", m, &i__1, k, &
c_b25, &work[work_offset], ldwork, &v[(*k + 1) *
v_dim1 + 1], ldv, &c_b14, &c__[(*k + 1) * c_dim1
+ 1], ldc);
}
/* W := W * V1 */
igraphdtrmm_("Right", "Upper", "No transpose", "Unit", m, k, &c_b14,
&v[v_offset], ldv, &work[work_offset], ldwork);
/* C1 := C1 - W */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
i__2 = *m;
for (i__ = 1; i__ <= i__2; ++i__) {
c__[i__ + j * c_dim1] -= work[i__ + j * work_dim1];
/* L170: */
}
/* L180: */
}
}
} else {
/* Let V = ( V1 V2 ) (V2: last K columns)
where V2 is unit lower triangular. */
if (igraphlsame_(side, "L")) {
/* Form H * C or H**T * C where C = ( C1 )
( C2 )
W := C**T * V**T = (C1**T * V1**T + C2**T * V2**T) (stored in WORK)
W := C2**T */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
igraphdcopy_(n, &c__[*m - *k + j + c_dim1], ldc, &work[j *
work_dim1 + 1], &c__1);
/* L190: */
}
/* W := W * V2**T */
igraphdtrmm_("Right", "Lower", "Transpose", "Unit", n, k, &c_b14, &
v[(*m - *k + 1) * v_dim1 + 1], ldv, &work[work_offset]
, ldwork);
if (*m > *k) {
/* W := W + C1**T * V1**T */
i__1 = *m - *k;
igraphdgemm_("Transpose", "Transpose", n, k, &i__1, &c_b14, &
c__[c_offset], ldc, &v[v_offset], ldv, &c_b14, &
work[work_offset], ldwork);
}
/* W := W * T**T or W * T */
igraphdtrmm_("Right", "Lower", transt, "Non-unit", n, k, &c_b14, &t[
t_offset], ldt, &work[work_offset], ldwork);
/* C := C - V**T * W**T */
if (*m > *k) {
/* C1 := C1 - V1**T * W**T */
i__1 = *m - *k;
igraphdgemm_("Transpose", "Transpose", &i__1, n, k, &c_b25, &v[
v_offset], ldv, &work[work_offset], ldwork, &
c_b14, &c__[c_offset], ldc);
}
/* W := W * V2 */
igraphdtrmm_("Right", "Lower", "No transpose", "Unit", n, k, &c_b14,
&v[(*m - *k + 1) * v_dim1 + 1], ldv, &work[
work_offset], ldwork);
/* C2 := C2 - W**T */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
i__2 = *n;
for (i__ = 1; i__ <= i__2; ++i__) {
c__[*m - *k + j + i__ * c_dim1] -= work[i__ + j *
work_dim1];
/* L200: */
}
/* L210: */
}
} else if (igraphlsame_(side, "R")) {
/* Form C * H or C * H' where C = ( C1 C2 )
W := C * V**T = (C1*V1**T + C2*V2**T) (stored in WORK)
W := C2 */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
igraphdcopy_(m, &c__[(*n - *k + j) * c_dim1 + 1], &c__1, &work[
j * work_dim1 + 1], &c__1);
/* L220: */
}
/* W := W * V2**T */
igraphdtrmm_("Right", "Lower", "Transpose", "Unit", m, k, &c_b14, &
v[(*n - *k + 1) * v_dim1 + 1], ldv, &work[work_offset]
, ldwork);
if (*n > *k) {
/* W := W + C1 * V1**T */
i__1 = *n - *k;
igraphdgemm_("No transpose", "Transpose", m, k, &i__1, &c_b14, &
c__[c_offset], ldc, &v[v_offset], ldv, &c_b14, &
work[work_offset], ldwork);
}
/* W := W * T or W * T**T */
igraphdtrmm_("Right", "Lower", trans, "Non-unit", m, k, &c_b14, &t[
t_offset], ldt, &work[work_offset], ldwork);
/* C := C - W * V */
if (*n > *k) {
/* C1 := C1 - W * V1 */
i__1 = *n - *k;
igraphdgemm_("No transpose", "No transpose", m, &i__1, k, &
c_b25, &work[work_offset], ldwork, &v[v_offset],
ldv, &c_b14, &c__[c_offset], ldc);
}
/* W := W * V2 */
igraphdtrmm_("Right", "Lower", "No transpose", "Unit", m, k, &c_b14,
&v[(*n - *k + 1) * v_dim1 + 1], ldv, &work[
work_offset], ldwork);
/* C1 := C1 - W */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
i__2 = *m;
for (i__ = 1; i__ <= i__2; ++i__) {
c__[i__ + (*n - *k + j) * c_dim1] -= work[i__ + j *
work_dim1];
/* L230: */
}
/* L240: */
}
}
}
}
return 0;
/* End of DLARFB */
} /* igraphdlarfb_ */