larzb - larzb: apply block reflector

Generated automatically by Doxygen for LAPACK from the source code. Version 3.12.0 Sun Jul 20 2025 01:40:05 larzb(3)

subroutineclarzb(characterside,charactertrans,characterdirect,characterstorev,integerm,integern,integerk,integerl,complex,dimension(ldv,*)v,integerldv,complex,dimension(ldt,*)t,integerldt,complex,dimension(ldc,*)c,integerldc,complex,dimension(ldwork,*)work,integerldwork)CLARZB applies a block reflector or its conjugate-transpose to a general matrix. Purpose: CLARZB applies a complex block reflector H or its transpose H**H to a complex distributed M-by-N C from the left or the right. Currently, only STOREV = 'R' and DIRECT = 'B' are supported. ParametersSIDE SIDE is CHARACTER*1 = 'L': apply H or H**H from the Left = 'R': apply H or H**H from the Right TRANS TRANS is CHARACTER*1 = 'N': apply H (No transpose) = 'C': apply H**H (Conjugate transpose) DIRECT DIRECT is CHARACTER*1 Indicates how H is formed from a product of elementary reflectors = 'F': H = H(1) H(2) . . . H(k) (Forward, not supported yet) = 'B': H = H(k) . . . H(2) H(1) (Backward) STOREV STOREV is CHARACTER*1 Indicates how the vectors which define the elementary reflectors are stored: = 'C': Columnwise (not supported yet) = 'R': Rowwise M M is INTEGER The number of rows of the matrix C. N N is INTEGER The number of columns of the matrix C. K K is INTEGER The order of the matrix T (= the number of elementary reflectors whose product defines the block reflector). L L is INTEGER The number of columns of the matrix V containing the meaningful part of the Householder reflectors. If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0. V V is COMPLEX array, dimension (LDV,NV). If STOREV = 'C', NV = K; if STOREV = 'R', NV = L. LDV LDV is INTEGER The leading dimension of the array V. If STOREV = 'C', LDV >= L; if STOREV = 'R', LDV >= K. T T is COMPLEX array, dimension (LDT,K) The triangular K-by-K matrix T in the representation of the block reflector. LDT LDT is INTEGER The leading dimension of the array T. LDT >= K. C C is COMPLEX array, dimension (LDC,N) On entry, the M-by-N matrix C. On exit, C is overwritten by H*C or H**H*C or C*H or C*H**H. LDC LDC is INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK WORK is COMPLEX array, dimension (LDWORK,K) LDWORK LDWORK is INTEGER The leading dimension of the array WORK. If SIDE = 'L', LDWORK >= max(1,N); if SIDE = 'R', LDWORK >= max(1,M). Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Contributors: A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA FurtherDetails:subroutinedlarzb(characterside,charactertrans,characterdirect,characterstorev,integerm,integern,integerk,integerl,doubleprecision,dimension(ldv,*)v,integerldv,doubleprecision,dimension(ldt,*)t,integerldt,doubleprecision,dimension(ldc,*)c,integerldc,doubleprecision,dimension(ldwork,*)work,integerldwork)DLARZB applies a block reflector or its transpose to a general matrix. Purpose: DLARZB applies a real block reflector H or its transpose H**T to a real distributed M-by-N C from the left or the right. Currently, only STOREV = 'R' and DIRECT = 'B' are supported. ParametersSIDE SIDE is CHARACTER*1 = 'L': apply H or H**T from the Left = 'R': apply H or H**T from the Right TRANS TRANS is CHARACTER*1 = 'N': apply H (No transpose) = 'C': apply H**T (Transpose) DIRECT DIRECT is CHARACTER*1 Indicates how H is formed from a product of elementary reflectors = 'F': H = H(1) H(2) . . . H(k) (Forward, not supported yet) = 'B': H = H(k) . . . H(2) H(1) (Backward) STOREV STOREV is CHARACTER*1 Indicates how the vectors which define the elementary reflectors are stored: = 'C': Columnwise (not supported yet) = 'R': Rowwise M M is INTEGER The number of rows of the matrix C. N N is INTEGER The number of columns of the matrix C. K K is INTEGER The order of the matrix T (= the number of elementary reflectors whose product defines the block reflector). L L is INTEGER The number of columns of the matrix V containing the meaningful part of the Householder reflectors. If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0. V V is DOUBLE PRECISION array, dimension (LDV,NV). If STOREV = 'C', NV = K; if STOREV = 'R', NV = L. LDV LDV is INTEGER The leading dimension of the array V. If STOREV = 'C', LDV >= L; if STOREV = 'R', LDV >= K. T T is DOUBLE PRECISION array, dimension (LDT,K) The triangular K-by-K matrix T in the representation of the block reflector. LDT LDT is INTEGER The leading dimension of the array T. LDT >= K. C 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. LDC LDC is INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK WORK is DOUBLE PRECISION array, dimension (LDWORK,K) LDWORK LDWORK is INTEGER The leading dimension of the array WORK. If SIDE = 'L', LDWORK >= max(1,N); if SIDE = 'R', LDWORK >= max(1,M). Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Contributors: A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA FurtherDetails:subroutineslarzb(characterside,charactertrans,characterdirect,characterstorev,integerm,integern,integerk,integerl,real,dimension(ldv,*)v,integerldv,real,dimension(ldt,*)t,integerldt,real,dimension(ldc,*)c,integerldc,real,dimension(ldwork,*)work,integerldwork)SLARZB applies a block reflector or its transpose to a general matrix. Purpose: SLARZB applies a real block reflector H or its transpose H**T to a real distributed M-by-N C from the left or the right. Currently, only STOREV = 'R' and DIRECT = 'B' are supported. ParametersSIDE SIDE is CHARACTER*1 = 'L': apply H or H**T from the Left = 'R': apply H or H**T from the Right TRANS TRANS is CHARACTER*1 = 'N': apply H (No transpose) = 'C': apply H**T (Transpose) DIRECT DIRECT is CHARACTER*1 Indicates how H is formed from a product of elementary reflectors = 'F': H = H(1) H(2) . . . H(k) (Forward, not supported yet) = 'B': H = H(k) . . . H(2) H(1) (Backward) STOREV STOREV is CHARACTER*1 Indicates how the vectors which define the elementary reflectors are stored: = 'C': Columnwise (not supported yet) = 'R': Rowwise M M is INTEGER The number of rows of the matrix C. N N is INTEGER The number of columns of the matrix C. K K is INTEGER The order of the matrix T (= the number of elementary reflectors whose product defines the block reflector). L L is INTEGER The number of columns of the matrix V containing the meaningful part of the Householder reflectors. If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0. V V is REAL array, dimension (LDV,NV). If STOREV = 'C', NV = K; if STOREV = 'R', NV = L. LDV LDV is INTEGER The leading dimension of the array V. If STOREV = 'C', LDV >= L; if STOREV = 'R', LDV >= K. T T is REAL array, dimension (LDT,K) The triangular K-by-K matrix T in the representation of the block reflector. LDT LDT is INTEGER The leading dimension of the array T. LDT >= K. C C is REAL 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. LDC LDC is INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK WORK is REAL array, dimension (LDWORK,K) LDWORK LDWORK is INTEGER The leading dimension of the array WORK. If SIDE = 'L', LDWORK >= max(1,N); if SIDE = 'R', LDWORK >= max(1,M). Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Contributors: A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA FurtherDetails:subroutinezlarzb(characterside,charactertrans,characterdirect,characterstorev,integerm,integern,integerk,integerl,complex*16,dimension(ldv,*)v,integerldv,complex*16,dimension(ldt,*)t,integerldt,complex*16,dimension(ldc,*)c,integerldc,complex*16,dimension(ldwork,*)work,integerldwork)ZLARZB applies a block reflector or its conjugate-transpose to a general matrix. Purpose: ZLARZB applies a complex block reflector H or its transpose H**H to a complex distributed M-by-N C from the left or the right. Currently, only STOREV = 'R' and DIRECT = 'B' are supported. ParametersSIDE SIDE is CHARACTER*1 = 'L': apply H or H**H from the Left = 'R': apply H or H**H from the Right TRANS TRANS is CHARACTER*1 = 'N': apply H (No transpose) = 'C': apply H**H (Conjugate transpose) DIRECT DIRECT is CHARACTER*1 Indicates how H is formed from a product of elementary reflectors = 'F': H = H(1) H(2) . . . H(k) (Forward, not supported yet) = 'B': H = H(k) . . . H(2) H(1) (Backward) STOREV STOREV is CHARACTER*1 Indicates how the vectors which define the elementary reflectors are stored: = 'C': Columnwise (not supported yet) = 'R': Rowwise M M is INTEGER The number of rows of the matrix C. N N is INTEGER The number of columns of the matrix C. K K is INTEGER The order of the matrix T (= the number of elementary reflectors whose product defines the block reflector). L L is INTEGER The number of columns of the matrix V containing the meaningful part of the Householder reflectors. If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0. V V is COMPLEX*16 array, dimension (LDV,NV). If STOREV = 'C', NV = K; if STOREV = 'R', NV = L. LDV LDV is INTEGER The leading dimension of the array V. If STOREV = 'C', LDV >= L; if STOREV = 'R', LDV >= K. T T is COMPLEX*16 array, dimension (LDT,K) The triangular K-by-K matrix T in the representation of the block reflector. LDT LDT is INTEGER The leading dimension of the array T. LDT >= K. C C is COMPLEX*16 array, dimension (LDC,N) On entry, the M-by-N matrix C. On exit, C is overwritten by H*C or H**H*C or C*H or C*H**H. LDC LDC is INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK WORK is COMPLEX*16 array, dimension (LDWORK,K) LDWORK LDWORK is INTEGER The leading dimension of the array WORK. If SIDE = 'L', LDWORK >= max(1,N); if SIDE = 'R', LDWORK >= max(1,M). Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Contributors: A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA FurtherDetails:

larzb - larzb: apply block reflector

Functions subroutine clarzb (side, trans, direct, storev, m, n, k, l, v, ldv, t, ldt, c, ldc, work, ldwork) CLARZB applies a block reflector or its conjugate-transpose to a general matrix. subroutine dlarzb (side, trans, direct, storev, m, n, k, l, v, ldv, t, ldt, c, ldc, work, ldwork) DLARZB applies a block reflector or its transpose to a general matrix. subroutine slarzb (side, trans, direct, storev, m, n, k, l, v, ldv, t, ldt, c, ldc, work, ldwork) SLARZB applies a block reflector or its transpose to a general matrix. subroutine zlarzb (side, trans, direct, storev, m, n, k, l, v, ldv, t, ldt, c, ldc, work, ldwork) ZLARZB applies a block reflector or its conjugate-transpose to a general matrix.