sormtr.f.html

来自「famous linear algebra library (LAPACK) p」· HTML 代码 · 共 248 行 · 第 1/2 页

</span><span class="comment">*</span><span class="comment">     .. External Functions ..
</span>      LOGICAL            <a name="LSAME.107"></a><a href="lsame.f.html#LSAME.1">LSAME</a>
      INTEGER            <a name="ILAENV.108"></a><a href="hfy-index.html#ILAENV">ILAENV</a>
      EXTERNAL           <a name="ILAENV.109"></a><a href="hfy-index.html#ILAENV">ILAENV</a>, <a name="LSAME.109"></a><a href="lsame.f.html#LSAME.1">LSAME</a>
<span class="comment">*</span><span class="comment">     ..
</span><span class="comment">*</span><span class="comment">     .. External Subroutines ..
</span>      EXTERNAL           <a name="SORMQL.112"></a><a href="sormql.f.html#SORMQL.1">SORMQL</a>, <a name="SORMQR.112"></a><a href="sormqr.f.html#SORMQR.1">SORMQR</a>, <a name="XERBLA.112"></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
<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">
</span><span class="comment">*</span><span class="comment">     Test the input arguments
</span><span class="comment">*</span><span class="comment">
</span>      INFO = 0
      LEFT = <a name="LSAME.122"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( SIDE, <span class="string">'L'</span> )
      UPPER = <a name="LSAME.123"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( UPLO, <span class="string">'U'</span> )
      LQUERY = ( LWORK.EQ.-1 )
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     NQ is the order of Q and NW is the minimum dimension of WORK
</span><span class="comment">*</span><span class="comment">
</span>      IF( LEFT ) THEN
         NQ = M
         NW = N
      ELSE
         NQ = N
         NW = M
      END IF
      IF( .NOT.LEFT .AND. .NOT.<a name="LSAME.135"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( SIDE, <span class="string">'R'</span> ) ) THEN
         INFO = -1
      ELSE IF( .NOT.UPPER .AND. .NOT.<a name="LSAME.137"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( UPLO, <span class="string">'L'</span> ) ) THEN
         INFO = -2
      ELSE IF( .NOT.<a name="LSAME.139"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( TRANS, <span class="string">'N'</span> ) .AND. .NOT.<a name="LSAME.139"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( TRANS, <span class="string">'T'</span> ) )
     $          THEN
         INFO = -3
      ELSE IF( M.LT.0 ) THEN
         INFO = -4
      ELSE IF( N.LT.0 ) THEN
         INFO = -5
      ELSE IF( LDA.LT.MAX( 1, NQ ) ) THEN
         INFO = -7
      ELSE IF( LDC.LT.MAX( 1, M ) ) THEN
         INFO = -10
      ELSE IF( LWORK.LT.MAX( 1, NW ) .AND. .NOT.LQUERY ) THEN
         INFO = -12
      END IF
<span class="comment">*</span><span class="comment">
</span>      IF( INFO.EQ.0 ) THEN
         IF( UPPER ) THEN
            IF( LEFT ) THEN
               NB = <a name="ILAENV.157"></a><a href="hfy-index.html#ILAENV">ILAENV</a>( 1, <span class="string">'<a name="SORMQL.157"></a><a href="sormql.f.html#SORMQL.1">SORMQL</a>'</span>, SIDE // TRANS, M-1, N, M-1,
     $                      -1 )
            ELSE
               NB = <a name="ILAENV.160"></a><a href="hfy-index.html#ILAENV">ILAENV</a>( 1, <span class="string">'<a name="SORMQL.160"></a><a href="sormql.f.html#SORMQL.1">SORMQL</a>'</span>, SIDE // TRANS, M, N-1, N-1,
     $                      -1 )
            END IF
         ELSE
            IF( LEFT ) THEN
               NB = <a name="ILAENV.165"></a><a href="hfy-index.html#ILAENV">ILAENV</a>( 1, <span class="string">'<a name="SORMQR.165"></a><a href="sormqr.f.html#SORMQR.1">SORMQR</a>'</span>, SIDE // TRANS, M-1, N, M-1,
     $                      -1 )
            ELSE
               NB = <a name="ILAENV.168"></a><a href="hfy-index.html#ILAENV">ILAENV</a>( 1, <span class="string">'<a name="SORMQR.168"></a><a href="sormqr.f.html#SORMQR.1">SORMQR</a>'</span>, SIDE // TRANS, M, N-1, N-1,
     $                      -1 )
            END IF
         END IF
         LWKOPT = MAX( 1, NW )*NB
         WORK( 1 ) = LWKOPT
      END IF
<span class="comment">*</span><span class="comment">
</span>      IF( INFO.NE.0 ) THEN
         CALL <a name="XERBLA.177"></a><a href="xerbla.f.html#XERBLA.1">XERBLA</a>( <span class="string">'<a name="SORMTR.177"></a><a href="sormtr.f.html#SORMTR.1">SORMTR</a>'</span>, -INFO )
         RETURN
      ELSE IF( LQUERY ) THEN
         RETURN
      END IF
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     Quick return if possible
</span><span class="comment">*</span><span class="comment">
</span>      IF( M.EQ.0 .OR. N.EQ.0 .OR. NQ.EQ.1 ) THEN
         WORK( 1 ) = 1
         RETURN
      END IF
<span class="comment">*</span><span class="comment">
</span>      IF( LEFT ) THEN
         MI = M - 1
         NI = N
      ELSE
         MI = M
         NI = N - 1
      END IF
<span class="comment">*</span><span class="comment">
</span>      IF( UPPER ) THEN
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">        Q was determined by a call to <a name="SSYTRD.200"></a><a href="ssytrd.f.html#SSYTRD.1">SSYTRD</a> with UPLO = 'U'
</span><span class="comment">*</span><span class="comment">
</span>         CALL <a name="SORMQL.202"></a><a href="sormql.f.html#SORMQL.1">SORMQL</a>( SIDE, TRANS, MI, NI, NQ-1, A( 1, 2 ), LDA, TAU, C,
     $                LDC, WORK, LWORK, IINFO )
      ELSE
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">        Q was determined by a call to <a name="SSYTRD.206"></a><a href="ssytrd.f.html#SSYTRD.1">SSYTRD</a> with UPLO = 'L'
</span><span class="comment">*</span><span class="comment">
</span>         IF( LEFT ) THEN
            I1 = 2
            I2 = 1
         ELSE
            I1 = 1
            I2 = 2
         END IF
         CALL <a name="SORMQR.215"></a><a href="sormqr.f.html#SORMQR.1">SORMQR</a>( SIDE, TRANS, MI, NI, NQ-1, A( 2, 1 ), LDA, TAU,
     $                C( I1, I2 ), LDC, WORK, LWORK, IINFO )
      END IF
      WORK( 1 ) = LWKOPT
      RETURN
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     End of <a name="SORMTR.221"></a><a href="sormtr.f.html#SORMTR.1">SORMTR</a>
</span><span class="comment">*</span><span class="comment">
</span>      END

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