#include "blaswrap.h" #include "f2c.h" /* Subroutine */ int dormr3_(char *side, char *trans, integer *m, integer *n, integer *k, integer *l, doublereal *a, integer *lda, doublereal *tau, doublereal *c__, integer *ldc, doublereal *work, integer *info) { /* -- LAPACK routine (version 3.1) -- Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. November 2006 Purpose ======= DORMR3 overwrites the general real m by n matrix C with Q * C if SIDE = 'L' and TRANS = 'N', or Q'* C if SIDE = 'L' and TRANS = 'T', or C * Q if SIDE = 'R' and TRANS = 'N', or C * Q' if SIDE = 'R' and TRANS = 'T', where Q is a real orthogonal matrix defined as the product of k elementary reflectors Q = H(1) H(2) . . . H(k) as returned by DTZRZF. Q is of order m if SIDE = 'L' and of order n if SIDE = 'R'. Arguments ========= SIDE (input) CHARACTER*1 = 'L': apply Q or Q' from the Left = 'R': apply Q or Q' from the Right TRANS (input) CHARACTER*1 = 'N': apply Q (No transpose) = 'T': apply Q' (Transpose) 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. K (input) INTEGER The number of elementary reflectors whose product defines the matrix Q. If SIDE = 'L', M >= K >= 0; if SIDE = 'R', N >= K >= 0. L (input) INTEGER The number of columns of the matrix A containing the meaningful part of the Householder reflectors. If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0. A (input) DOUBLE PRECISION array, dimension (LDA,M) if SIDE = 'L', (LDA,N) if SIDE = 'R' The i-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by DTZRZF in the last k rows of its array argument A. A is modified by the routine but restored on exit. LDA (input) INTEGER The leading dimension of the array A. LDA >= max(1,K). TAU (input) DOUBLE PRECISION array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by DTZRZF. C (input/output) DOUBLE PRECISION array, dimension (LDC,N) On entry, the m-by-n matrix C. On exit, C is overwritten by Q*C or Q'*C or C*Q' or C*Q. LDC (input) INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK (workspace) DOUBLE PRECISION array, dimension (N) if SIDE = 'L', (M) if SIDE = 'R' INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value Further Details =============== Based on contributions by A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA ===================================================================== Test the input arguments Parameter adjustments */ /* System generated locals */ integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2; /* Local variables */ static integer i__, i1, i2, i3, ja, ic, jc, mi, ni, nq; static logical left; extern logical lsame_(char *, char *); extern /* Subroutine */ int dlarz_(char *, integer *, integer *, integer * , doublereal *, integer *, doublereal *, doublereal *, integer *, doublereal *), xerbla_(char *, integer *); static logical notran; a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; --work; /* Function Body */ *info = 0; left = lsame_(side, "L"); notran = lsame_(trans, "N"); /* NQ is the order of Q */ if (left) { nq = *m; } else { nq = *n; } if (! left && ! lsame_(side, "R")) { *info = -1; } else if (! notran && ! lsame_(trans, "T")) { *info = -2; } else if (*m < 0) { *info = -3; } else if (*n < 0) { *info = -4; } else if (*k < 0 || *k > nq) { *info = -5; } else if (*l < 0 || left && *l > *m || ! left && *l > *n) { *info = -6; } else if (*lda < max(1,*k)) { *info = -8; } else if (*ldc < max(1,*m)) { *info = -11; } if (*info != 0) { i__1 = -(*info); xerbla_("DORMR3", &i__1); return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0 || *k == 0) { return 0; } if (left && ! notran || ! left && notran) { i1 = 1; i2 = *k; i3 = 1; } else { i1 = *k; i2 = 1; i3 = -1; } if (left) { ni = *n; ja = *m - *l + 1; jc = 1; } else { mi = *m; ja = *n - *l + 1; ic = 1; } i__1 = i2; i__2 = i3; for (i__ = i1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { if (left) { /* H(i) or H(i)' is applied to C(i:m,1:n) */ mi = *m - i__ + 1; ic = i__; } else { /* H(i) or H(i)' is applied to C(1:m,i:n) */ ni = *n - i__ + 1; jc = i__; } /* Apply H(i) or H(i)' */ dlarz_(side, &mi, &ni, l, &a[i__ + ja * a_dim1], lda, &tau[i__], &c__[ ic + jc * c_dim1], ldc, &work[1]); /* L10: */ } return 0; /* End of DORMR3 */ } /* dormr3_ */