sopmtr (l)  Linux Manuals
sopmtr: overwrites the general real MbyN matrix C with SIDE = aqLaq SIDE = aqRaq TRANS = aqNaq
NAME
SOPMTR  overwrites the general real MbyN matrix C with SIDE = aqLaq SIDE = aqRaq TRANS = aqNaqSYNOPSIS
 SUBROUTINE SOPMTR(
 SIDE, UPLO, TRANS, M, N, AP, TAU, C, LDC, WORK, INFO )
 CHARACTER SIDE, TRANS, UPLO
 INTEGER INFO, LDC, M, N
 REAL AP( * ), C( LDC, * ), TAU( * ), WORK( * )
PURPOSE
SOPMTR overwrites the general real MbyN matrix C with TRANS = aqTaq: Q**T * C C * Q**Twhere Q is a real orthogonal matrix of order nq, with nq = m if SIDE = aqLaq and nq = n if SIDE = aqRaq. Q is defined as the product of nq1 elementary reflectors, as returned by SSPTRD using packed storage:
if UPLO = aqUaq, Q = H(nq1) . . . H(2) H(1);
if UPLO = aqLaq, Q = H(1) H(2) . . . H(nq1).
ARGUMENTS
 SIDE (input) CHARACTER*1

= aqLaq: apply Q or Q**T from the Left;
= aqRaq: apply Q or Q**T from the Right.  UPLO (input) CHARACTER*1

= aqUaq: Upper triangular packed storage used in previous call to SSPTRD; = aqLaq: Lower triangular packed storage used in previous call to SSPTRD.  TRANS (input) CHARACTER*1

= aqNaq: No transpose, apply Q;
= aqTaq: Transpose, apply Q**T.  M (input) INTEGER
 The number of rows of the matrix C. M >= 0.
 N (input) INTEGER
 The number of columns of the matrix C. N >= 0.
 AP (input) REAL array, dimension
 (M*(M+1)/2) if SIDE = aqLaq (N*(N+1)/2) if SIDE = aqRaq The vectors which define the elementary reflectors, as returned by SSPTRD. AP is modified by the routine but restored on exit.
 TAU (input) REAL array, dimension (M1) if SIDE = aqLaq
 or (N1) if SIDE = aqRaq TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by SSPTRD.
 C (input/output) REAL array, dimension (LDC,N)
 On entry, the MbyN matrix C. On exit, C is overwritten by Q*C or Q**T*C or C*Q**T or C*Q.
 LDC (input) INTEGER
 The leading dimension of the array C. LDC >= max(1,M).
 WORK (workspace) REAL array, dimension
 (N) if SIDE = aqLaq (M) if SIDE = aqRaq
 INFO (output) INTEGER

= 0: successful exit
< 0: if INFO = i, the ith argument had an illegal value