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SUBROUTINE <a name="DORMQR.1"></a><a href="dormqr.f.html#DORMQR.1">DORMQR</a>( SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC,
$ WORK, LWORK, INFO )
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> -- LAPACK routine (version 3.1) --
</span><span class="comment">*</span><span class="comment"> Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
</span><span class="comment">*</span><span class="comment"> November 2006
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> .. Scalar Arguments ..
</span> CHARACTER SIDE, TRANS
INTEGER INFO, K, LDA, LDC, LWORK, M, N
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. Array Arguments ..
</span> DOUBLE PRECISION A( LDA, * ), C( LDC, * ), TAU( * ), WORK( * )
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Purpose
</span><span class="comment">*</span><span class="comment"> =======
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> <a name="DORMQR.19"></a><a href="dormqr.f.html#DORMQR.1">DORMQR</a> overwrites the general real M-by-N matrix C with
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> SIDE = 'L' SIDE = 'R'
</span><span class="comment">*</span><span class="comment"> TRANS = 'N': Q * C C * Q
</span><span class="comment">*</span><span class="comment"> TRANS = 'T': Q**T * C C * Q**T
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> where Q is a real orthogonal matrix defined as the product of k
</span><span class="comment">*</span><span class="comment"> elementary reflectors
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Q = H(1) H(2) . . . H(k)
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> as returned by <a name="DGEQRF.30"></a><a href="dgeqrf.f.html#DGEQRF.1">DGEQRF</a>. Q is of order M if SIDE = 'L' and of order N
</span><span class="comment">*</span><span class="comment"> if SIDE = 'R'.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Arguments
</span><span class="comment">*</span><span class="comment"> =========
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> SIDE (input) CHARACTER*1
</span><span class="comment">*</span><span class="comment"> = 'L': apply Q or Q**T from the Left;
</span><span class="comment">*</span><span class="comment"> = 'R': apply Q or Q**T from the Right.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> TRANS (input) CHARACTER*1
</span><span class="comment">*</span><span class="comment"> = 'N': No transpose, apply Q;
</span><span class="comment">*</span><span class="comment"> = 'T': Transpose, apply Q**T.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> M (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The number of rows of the matrix C. M >= 0.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> N (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The number of columns of the matrix C. N >= 0.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> K (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The number of elementary reflectors whose product defines
</span><span class="comment">*</span><span class="comment"> the matrix Q.
</span><span class="comment">*</span><span class="comment"> If SIDE = 'L', M >= K >= 0;
</span><span class="comment">*</span><span class="comment"> if SIDE = 'R', N >= K >= 0.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> A (input) DOUBLE PRECISION array, dimension (LDA,K)
</span><span class="comment">*</span><span class="comment"> The i-th column must contain the vector which defines the
</span><span class="comment">*</span><span class="comment"> elementary reflector H(i), for i = 1,2,...,k, as returned by
</span><span class="comment">*</span><span class="comment"> <a name="DGEQRF.59"></a><a href="dgeqrf.f.html#DGEQRF.1">DGEQRF</a> in the first k columns of its array argument A.
</span><span class="comment">*</span><span class="comment"> A is modified by the routine but restored on exit.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> LDA (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The leading dimension of the array A.
</span><span class="comment">*</span><span class="comment"> If SIDE = 'L', LDA >= max(1,M);
</span><span class="comment">*</span><span class="comment"> if SIDE = 'R', LDA >= max(1,N).
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> TAU (input) DOUBLE PRECISION array, dimension (K)
</span><span class="comment">*</span><span class="comment"> TAU(i) must contain the scalar factor of the elementary
</span><span class="comment">*</span><span class="comment"> reflector H(i), as returned by <a name="DGEQRF.69"></a><a href="dgeqrf.f.html#DGEQRF.1">DGEQRF</a>.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> C (input/output) DOUBLE PRECISION array, dimension (LDC,N)
</span><span class="comment">*</span><span class="comment"> On entry, the M-by-N matrix C.
</span><span class="comment">*</span><span class="comment"> On exit, C is overwritten by Q*C or Q**T*C or C*Q**T or C*Q.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> LDC (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The leading dimension of the array C. LDC >= max(1,M).
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> WORK (workspace/output) DOUBLE PRECISION array, dimension (MAX(1,LWORK))
</span><span class="comment">*</span><span class="comment"> On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> LWORK (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The dimension of the array WORK.
</span><span class="comment">*</span><span class="comment"> If SIDE = 'L', LWORK >= max(1,N);
</span><span class="comment">*</span><span class="comment"> if SIDE = 'R', LWORK >= max(1,M).
</span><span class="comment">*</span><span class="comment"> For optimum performance LWORK >= N*NB if SIDE = 'L', and
</span><span class="comment">*</span><span class="comment"> LWORK >= M*NB if SIDE = 'R', where NB is the optimal
</span><span class="comment">*</span><span class="comment"> blocksize.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> If LWORK = -1, then a workspace query is assumed; the routine
</span><span class="comment">*</span><span class="comment"> only calculates the optimal size of the WORK array, returns
</span><span class="comment">*</span><span class="comment"> this value as the first entry of the WORK array, and no error
</span><span class="comment">*</span><span class="comment"> message related to LWORK is issued by <a name="XERBLA.92"></a><a href="xerbla.f.html#XERBLA.1">XERBLA</a>.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> INFO (output) INTEGER
</span><span class="comment">*</span><span class="comment"> = 0: successful exit
</span><span class="comment">*</span><span class="comment"> < 0: if INFO = -i, the i-th argument had an illegal value
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> =====================================================================
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> .. Parameters ..
</span> INTEGER NBMAX, LDT
PARAMETER ( NBMAX = 64, LDT = NBMAX+1 )
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. Local Scalars ..
</span> LOGICAL LEFT, LQUERY, NOTRAN
INTEGER I, I1, I2, I3, IB, IC, IINFO, IWS, JC, LDWORK,
$ LWKOPT, MI, NB, NBMIN, NI, NQ, NW
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. Local Arrays ..
</span> DOUBLE PRECISION T( LDT, NBMAX )
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. External Functions ..
</span> LOGICAL <a name="LSAME.113"></a><a href="lsame.f.html#LSAME.1">LSAME</a>
INTEGER <a name="ILAENV.114"></a><a href="hfy-index.html#ILAENV">ILAENV</a>
EXTERNAL <a name="LSAME.115"></a><a href="lsame.f.html#LSAME.1">LSAME</a>, <a name="ILAENV.115"></a><a href="hfy-index.html#ILAENV">ILAENV</a>
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. External Subroutines ..
</span> EXTERNAL <a name="DLARFB.118"></a><a href="dlarfb.f.html#DLARFB.1">DLARFB</a>, <a name="DLARFT.118"></a><a href="dlarft.f.html#DLARFT.1">DLARFT</a>, <a name="DORM2R.118"></a><a href="dorm2r.f.html#DORM2R.1">DORM2R</a>, <a name="XERBLA.118"></a><a href="xerbla.f.html#XERBLA.1">XERBLA</a>
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. Intrinsic Functions ..
</span> INTRINSIC MAX, MIN
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. Executable Statements ..
</span><span class="comment">*</span><span class="comment">
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