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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 &gt;= 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 &gt;= 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 &gt;= K &gt;= 0;
</span><span class="comment">*</span><span class="comment">          if SIDE = 'R', N &gt;= K &gt;= 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 &gt;= max(1,M);
</span><span class="comment">*</span><span class="comment">          if SIDE = 'R', LDA &gt;= 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 &gt;= 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 &gt;= max(1,N);
</span><span class="comment">*</span><span class="comment">          if SIDE = 'R', LWORK &gt;= max(1,M).
</span><span class="comment">*</span><span class="comment">          For optimum performance LWORK &gt;= N*NB if SIDE = 'L', and
</span><span class="comment">*</span><span class="comment">          LWORK &gt;= 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">          &lt; 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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