/* ./src_f77/sormr3.f -- translated by f2c (version 20030320).
   You must link the resulting object file with the libraries:
	-lf2c -lm   (in that order)
*/

#include <punc/vf2c.h>

/* Subroutine */ int sormr3_(char *side, char *trans, integer *m, integer *n, 
	integer *k, integer *l, real *a, integer *lda, real *tau, real *c__, 
	integer *ldc, real *work, integer *info, ftnlen side_len, ftnlen 
	trans_len)
{
    /* 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 *, ftnlen, ftnlen);
    extern /* Subroutine */ int slarz_(char *, integer *, integer *, integer *
	    , real *, integer *, real *, real *, integer *, real *, ftnlen), 
	    xerbla_(char *, integer *, ftnlen);
    static logical notran;


/*  -- LAPACK routine (version 3.0) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd., */
/*     Courant Institute, Argonne National Lab, and Rice University */
/*     June 30, 1999 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  SORMR3 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 STZRZF. 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) REAL 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 */
/*          STZRZF 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) REAL array, dimension (K) */
/*          TAU(i) must contain the scalar factor of the elementary */
/*          reflector H(i), as returned by STZRZF. */

/*  C       (input/output) REAL 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) REAL 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 */

/*  ===================================================================== */

/*     .. Local Scalars .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input arguments */

    /* Parameter adjustments */
    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", (ftnlen)1, (ftnlen)1);
    notran = lsame_(trans, "N", (ftnlen)1, (ftnlen)1);

/*     NQ is the order of Q */

    if (left) {
	nq = *m;
    } else {
	nq = *n;
    }
    if (! left && ! lsame_(side, "R", (ftnlen)1, (ftnlen)1)) {
	*info = -1;
    } else if (! notran && ! lsame_(trans, "T", (ftnlen)1, (ftnlen)1)) {
	*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_("SORMR3", &i__1, (ftnlen)6);
	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)' */

	slarz_(side, &mi, &ni, l, &a[i__ + ja * a_dim1], lda, &tau[i__], &c__[
		ic + jc * c_dim1], ldc, &work[1], (ftnlen)1);

/* L10: */
    }

    return 0;

/*     End of SORMR3 */

} /* sormr3_ */

