cunm2r.f.html

来自「famous linear algebra library (LAPACK) p」· HTML 代码 · 共 226 行 · 第 1/2 页

<span class="comment">*</span><span class="comment">     ..
</span><span class="comment">*</span><span class="comment">     .. Local Scalars ..
</span>      LOGICAL            LEFT, NOTRAN
      INTEGER            I, I1, I2, I3, IC, JC, MI, NI, NQ
      COMPLEX            AII, TAUI
<span class="comment">*</span><span class="comment">     ..
</span><span class="comment">*</span><span class="comment">     .. External Functions ..
</span>      LOGICAL            <a name="LSAME.102"></a><a href="lsame.f.html#LSAME.1">LSAME</a>
      EXTERNAL           <a name="LSAME.103"></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="CLARF.106"></a><a href="clarf.f.html#CLARF.1">CLARF</a>, <a name="XERBLA.106"></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          CONJG, 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.116"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( SIDE, <span class="string">'L'</span> )
      NOTRAN = <a name="LSAME.117"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( TRANS, <span class="string">'N'</span> )
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     NQ is the order of Q
</span><span class="comment">*</span><span class="comment">
</span>      IF( LEFT ) THEN
         NQ = M
      ELSE
         NQ = N
      END IF
      IF( .NOT.LEFT .AND. .NOT.<a name="LSAME.126"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( SIDE, <span class="string">'R'</span> ) ) THEN
         INFO = -1
      ELSE IF( .NOT.NOTRAN .AND. .NOT.<a name="LSAME.128"></a><a href="lsame.f.html#LSAME.1">LSAME</a>( TRANS, <span class="string">'C'</span> ) ) THEN
         INFO = -2
      ELSE IF( M.LT.0 ) THEN
         INFO = -3
      ELSE IF( N.LT.0 ) THEN
         INFO = -4
      ELSE IF( K.LT.0 .OR. K.GT.NQ ) THEN
         INFO = -5
      ELSE IF( LDA.LT.MAX( 1, NQ ) ) THEN
         INFO = -7
      ELSE IF( LDC.LT.MAX( 1, M ) ) THEN
         INFO = -10
      END IF
      IF( INFO.NE.0 ) THEN
         CALL <a name="XERBLA.142"></a><a href="xerbla.f.html#XERBLA.1">XERBLA</a>( <span class="string">'<a name="CUNM2R.142"></a><a href="cunm2r.f.html#CUNM2R.1">CUNM2R</a>'</span>, -INFO )
         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. K.EQ.0 )
     $   RETURN
<span class="comment">*</span><span class="comment">
</span>      IF( ( LEFT .AND. .NOT.NOTRAN .OR. .NOT.LEFT .AND. NOTRAN ) ) THEN
         I1 = 1
         I2 = K
         I3 = 1
      ELSE
         I1 = K
         I2 = 1
         I3 = -1
      END IF
<span class="comment">*</span><span class="comment">
</span>      IF( LEFT ) THEN
         NI = N
         JC = 1
      ELSE
         MI = M
         IC = 1
      END IF
<span class="comment">*</span><span class="comment">
</span>      DO 10 I = I1, I2, I3
         IF( LEFT ) THEN
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">           H(i) or H(i)' is applied to C(i:m,1:n)
</span><span class="comment">*</span><span class="comment">
</span>            MI = M - I + 1
            IC = I
         ELSE
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">           H(i) or H(i)' is applied to C(1:m,i:n)
</span><span class="comment">*</span><span class="comment">
</span>            NI = N - I + 1
            JC = I
         END IF
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">        Apply H(i) or H(i)'
</span><span class="comment">*</span><span class="comment">
</span>         IF( NOTRAN ) THEN
            TAUI = TAU( I )
         ELSE
            TAUI = CONJG( TAU( I ) )
         END IF
         AII = A( I, I )
         A( I, I ) = ONE
         CALL <a name="CLARF.193"></a><a href="clarf.f.html#CLARF.1">CLARF</a>( SIDE, MI, NI, A( I, I ), 1, TAUI, C( IC, JC ), LDC,
     $               WORK )
         A( I, I ) = AII
   10 CONTINUE
      RETURN
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     End of <a name="CUNM2R.199"></a><a href="cunm2r.f.html#CUNM2R.1">CUNM2R</a>
</span><span class="comment">*</span><span class="comment">
</span>      END

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