.TH "SRC/stpmqrt.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME SRC/stpmqrt.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBstpmqrt\fP (side, trans, m, n, k, l, nb, v, ldv, t, ldt, a, lda, b, ldb, work, info)" .br .RI "\fBSTPMQRT\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine stpmqrt (character side, character trans, integer m, integer n, integer k, integer l, integer nb, real, dimension( ldv, * ) v, integer ldv, real, dimension( ldt, * ) t, integer ldt, real, dimension( lda, * ) a, integer lda, real, dimension( ldb, * ) b, integer ldb, real, dimension( * ) work, integer info)" .PP \fBSTPMQRT\fP .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> STPMQRT applies a real orthogonal matrix Q obtained from a !> real block reflector H to a general !> real matrix C, which consists of two blocks A and B\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fISIDE\fP .PP .nf !> SIDE is CHARACTER*1 !> = 'L': apply Q or Q^T from the Left; !> = 'R': apply Q or Q^T from the Right\&. !> .fi .PP .br \fITRANS\fP .PP .nf !> TRANS is CHARACTER*1 !> = 'N': No transpose, apply Q; !> = 'T': Transpose, apply Q^T\&. !> .fi .PP .br \fIM\fP .PP .nf !> M is INTEGER !> The number of rows of the matrix B\&. M >= 0\&. !> .fi .PP .br \fIN\fP .PP .nf !> N is INTEGER !> The number of columns of the matrix B\&. N >= 0\&. !> .fi .PP .br \fIK\fP .PP .nf !> K is INTEGER !> The number of elementary reflectors whose product defines !> the matrix Q\&. !> .fi .PP .br \fIL\fP .PP .nf !> L is INTEGER !> The order of the trapezoidal part of V\&. !> K >= L >= 0\&. See Further Details\&. !> .fi .PP .br \fINB\fP .PP .nf !> NB is INTEGER !> The block size used for the storage of T\&. K >= NB >= 1\&. !> This must be the same value of NB used to generate T !> in CTPQRT\&. !> .fi .PP .br \fIV\fP .PP .nf !> V is REAL array, dimension (LDV,K) !> The i-th column must contain the vector which defines the !> elementary reflector H(i), for i = 1,2,\&.\&.\&.,k, as returned by !> CTPQRT in B\&. See Further Details\&. !> .fi .PP .br \fILDV\fP .PP .nf !> LDV is INTEGER !> The leading dimension of the array V\&. !> If SIDE = 'L', LDV >= max(1,M); !> if SIDE = 'R', LDV >= max(1,N)\&. !> .fi .PP .br \fIT\fP .PP .nf !> T is REAL array, dimension (LDT,K) !> The upper triangular factors of the block reflectors !> as returned by CTPQRT, stored as a NB-by-K matrix\&. !> .fi .PP .br \fILDT\fP .PP .nf !> LDT is INTEGER !> The leading dimension of the array T\&. LDT >= NB\&. !> .fi .PP .br \fIA\fP .PP .nf !> A is REAL array, dimension !> (LDA,N) if SIDE = 'L' or !> (LDA,K) if SIDE = 'R' !> On entry, the K-by-N or M-by-K matrix A\&. !> On exit, A is overwritten by the corresponding block of !> Q*C or Q^T*C or C*Q or C*Q^T\&. See Further Details\&. !> .fi .PP .br \fILDA\fP .PP .nf !> LDA is INTEGER !> The leading dimension of the array A\&. !> If SIDE = 'L', LDC >= max(1,K); !> If SIDE = 'R', LDC >= max(1,M)\&. !> .fi .PP .br \fIB\fP .PP .nf !> B is REAL array, dimension (LDB,N) !> On entry, the M-by-N matrix B\&. !> On exit, B is overwritten by the corresponding block of !> Q*C or Q^T*C or C*Q or C*Q^T\&. See Further Details\&. !> .fi .PP .br \fILDB\fP .PP .nf !> LDB is INTEGER !> The leading dimension of the array B\&. !> LDB >= max(1,M)\&. !> .fi .PP .br \fIWORK\fP .PP .nf !> WORK is REAL array\&. The dimension of WORK is !> N*NB if SIDE = 'L', or M*NB if SIDE = 'R'\&. !> .fi .PP .br \fIINFO\fP .PP .nf !> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value !> .fi .PP .RE .PP \fBAuthor\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP \fBFurther Details:\fP .RS 4 .PP .nf !> !> The columns of the pentagonal matrix V contain the elementary reflectors !> H(1), H(2), \&.\&.\&., H(K); V is composed of a rectangular block V1 and a !> trapezoidal block V2: !> !> V = [V1] !> [V2]\&. !> !> The size of the trapezoidal block V2 is determined by the parameter L, !> where 0 <= L <= K; V2 is upper trapezoidal, consisting of the first L !> rows of a K-by-K upper triangular matrix\&. If L=K, V2 is upper triangular; !> if L=0, there is no trapezoidal block, hence V = V1 is rectangular\&. !> !> If SIDE = 'L': C = [A] where A is K-by-N, B is M-by-N and V is M-by-K\&. !> [B] !> !> If SIDE = 'R': C = [A B] where A is M-by-K, B is M-by-N and V is N-by-K\&. !> !> The real orthogonal matrix Q is formed from V and T\&. !> !> If TRANS='N' and SIDE='L', C is on exit replaced with Q * C\&. !> !> If TRANS='T' and SIDE='L', C is on exit replaced with Q^T * C\&. !> !> If TRANS='N' and SIDE='R', C is on exit replaced with C * Q\&. !> !> If TRANS='T' and SIDE='R', C is on exit replaced with C * Q^T\&. !> .fi .PP .RE .PP .PP Definition at line \fB214\fP of file \fBstpmqrt\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.