SRC/sorm22.f(3) Library Functions Manual SRC/sorm22.f(3) NAME SRC/sorm22.f SYNOPSIS Functions/Subroutines subroutine sorm22 (side, trans, m, n, n1, n2, q, ldq, c, ldc, work, lwork, info) SORM22 multiplies a general matrix by a banded orthogonal matrix. Function/Subroutine Documentation subroutine sorm22 (character side, character trans, integer m, integer n, integer n1, integer n2, real, dimension( ldq, * ) q, integer ldq, real, dimension( ldc, * ) c, integer ldc, real, dimension( * ) work, integer lwork, integer info) SORM22 multiplies a general matrix by a banded orthogonal matrix. Purpose SORM22 overwrites the general real M-by-N matrix C with SIDE = 'L' SIDE = 'R' TRANS = 'N': Q * C C * Q TRANS = 'T': Q**T * C C * Q**T where Q is a real orthogonal matrix of order NQ, with NQ = M if SIDE = 'L' and NQ = N if SIDE = 'R'. The orthogonal matrix Q processes a 2-by-2 block structure [ Q11 Q12 ] Q = [ ] [ Q21 Q22 ], where Q12 is an N1-by-N1 lower triangular matrix and Q21 is an N2-by-N2 upper triangular matrix. Parameters SIDE SIDE is CHARACTER*1 = 'L': apply Q or Q**T from the Left; = 'R': apply Q or Q**T from the Right. TRANS TRANS is CHARACTER*1 = 'N': apply Q (No transpose); = 'C': apply Q**T (Conjugate transpose). M M is INTEGER The number of rows of the matrix C. M >= 0. N N is INTEGER The number of columns of the matrix C. N >= 0. N1 N2 N1 is INTEGER N2 is INTEGER The dimension of Q12 and Q21, respectively. N1, N2 >= 0. The following requirement must be satisfied: N1 + N2 = M if SIDE = 'L' and N1 + N2 = N if SIDE = 'R'. Q Q is REAL array, dimension (LDQ,M) if SIDE = 'L' (LDQ,N) if SIDE = 'R' LDQ LDQ is INTEGER The leading dimension of the array Q. LDQ >= max(1,M) if SIDE = 'L'; LDQ >= max(1,N) if SIDE = 'R'. C C is REAL array, dimension (LDC,N) On entry, the M-by-N matrix C. On exit, C is overwritten by Q*C or Q**T*C or C*Q**T or C*Q. LDC LDC is INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK WORK is REAL array, dimension (MAX(1,LWORK)) On exit, if INFO = 0, WORK(1) returns the optimal LWORK. LWORK LWORK is INTEGER The dimension of the array WORK. If SIDE = 'L', LWORK >= max(1,N); if SIDE = 'R', LWORK >= max(1,M). For optimum performance LWORK >= M*N. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line 161 of file sorm22.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 SRC/sorm22.f(3)