.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 'triangular-pentagonal' 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\&.