ctpmv.f.html

来自「famous linear algebra library (LAPACK) p」· HTML 代码 · 共 351 行 · 第 1/2 页

<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">        Form  x:= A*x.
</span><span class="comment">*</span><span class="comment">
</span>          IF (<a name="LSAME.161"></a><a href="lsame.f.html#LSAME.1">LSAME</a>(UPLO,<span class="string">'U'</span>)) THEN
              KK = 1
              IF (INCX.EQ.1) THEN
                  DO 20 J = 1,N
                      IF (X(J).NE.ZERO) THEN
                          TEMP = X(J)
                          K = KK
                          DO 10 I = 1,J - 1
                              X(I) = X(I) + TEMP*AP(K)
                              K = K + 1
   10                     CONTINUE
                          IF (NOUNIT) X(J) = X(J)*AP(KK+J-1)
                      END IF
                      KK = KK + J
   20             CONTINUE
              ELSE
                  JX = KX
                  DO 40 J = 1,N
                      IF (X(JX).NE.ZERO) THEN
                          TEMP = X(JX)
                          IX = KX
                          DO 30 K = KK,KK + J - 2
                              X(IX) = X(IX) + TEMP*AP(K)
                              IX = IX + INCX
   30                     CONTINUE
                          IF (NOUNIT) X(JX) = X(JX)*AP(KK+J-1)
                      END IF
                      JX = JX + INCX
                      KK = KK + J
   40             CONTINUE
              END IF
          ELSE
              KK = (N* (N+1))/2
              IF (INCX.EQ.1) THEN
                  DO 60 J = N,1,-1
                      IF (X(J).NE.ZERO) THEN
                          TEMP = X(J)
                          K = KK
                          DO 50 I = N,J + 1,-1
                              X(I) = X(I) + TEMP*AP(K)
                              K = K - 1
   50                     CONTINUE
                          IF (NOUNIT) X(J) = X(J)*AP(KK-N+J)
                      END IF
                      KK = KK - (N-J+1)
   60             CONTINUE
              ELSE
                  KX = KX + (N-1)*INCX
                  JX = KX
                  DO 80 J = N,1,-1
                      IF (X(JX).NE.ZERO) THEN
                          TEMP = X(JX)
                          IX = KX
                          DO 70 K = KK,KK - (N- (J+1)),-1
                              X(IX) = X(IX) + TEMP*AP(K)
                              IX = IX - INCX
   70                     CONTINUE
                          IF (NOUNIT) X(JX) = X(JX)*AP(KK-N+J)
                      END IF
                      JX = JX - INCX
                      KK = KK - (N-J+1)
   80             CONTINUE
              END IF
          END IF
      ELSE
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">        Form  x := A'*x  or  x := conjg( A' )*x.
</span><span class="comment">*</span><span class="comment">
</span>          IF (<a name="LSAME.229"></a><a href="lsame.f.html#LSAME.1">LSAME</a>(UPLO,<span class="string">'U'</span>)) THEN
              KK = (N* (N+1))/2
              IF (INCX.EQ.1) THEN
                  DO 110 J = N,1,-1
                      TEMP = X(J)
                      K = KK - 1
                      IF (NOCONJ) THEN
                          IF (NOUNIT) TEMP = TEMP*AP(KK)
                          DO 90 I = J - 1,1,-1
                              TEMP = TEMP + AP(K)*X(I)
                              K = K - 1
   90                     CONTINUE
                      ELSE
                          IF (NOUNIT) TEMP = TEMP*CONJG(AP(KK))
                          DO 100 I = J - 1,1,-1
                              TEMP = TEMP + CONJG(AP(K))*X(I)
                              K = K - 1
  100                     CONTINUE
                      END IF
                      X(J) = TEMP
                      KK = KK - J
  110             CONTINUE
              ELSE
                  JX = KX + (N-1)*INCX
                  DO 140 J = N,1,-1
                      TEMP = X(JX)
                      IX = JX
                      IF (NOCONJ) THEN
                          IF (NOUNIT) TEMP = TEMP*AP(KK)
                          DO 120 K = KK - 1,KK - J + 1,-1
                              IX = IX - INCX
                              TEMP = TEMP + AP(K)*X(IX)
  120                     CONTINUE
                      ELSE
                          IF (NOUNIT) TEMP = TEMP*CONJG(AP(KK))
                          DO 130 K = KK - 1,KK - J + 1,-1
                              IX = IX - INCX
                              TEMP = TEMP + CONJG(AP(K))*X(IX)
  130                     CONTINUE
                      END IF
                      X(JX) = TEMP
                      JX = JX - INCX
                      KK = KK - J
  140             CONTINUE
              END IF
          ELSE
              KK = 1
              IF (INCX.EQ.1) THEN
                  DO 170 J = 1,N
                      TEMP = X(J)
                      K = KK + 1
                      IF (NOCONJ) THEN
                          IF (NOUNIT) TEMP = TEMP*AP(KK)
                          DO 150 I = J + 1,N
                              TEMP = TEMP + AP(K)*X(I)
                              K = K + 1
  150                     CONTINUE
                      ELSE
                          IF (NOUNIT) TEMP = TEMP*CONJG(AP(KK))
                          DO 160 I = J + 1,N
                              TEMP = TEMP + CONJG(AP(K))*X(I)
                              K = K + 1
  160                     CONTINUE
                      END IF
                      X(J) = TEMP
                      KK = KK + (N-J+1)
  170             CONTINUE
              ELSE
                  JX = KX
                  DO 200 J = 1,N
                      TEMP = X(JX)
                      IX = JX
                      IF (NOCONJ) THEN
                          IF (NOUNIT) TEMP = TEMP*AP(KK)
                          DO 180 K = KK + 1,KK + N - J
                              IX = IX + INCX
                              TEMP = TEMP + AP(K)*X(IX)
  180                     CONTINUE
                      ELSE
                          IF (NOUNIT) TEMP = TEMP*CONJG(AP(KK))
                          DO 190 K = KK + 1,KK + N - J
                              IX = IX + INCX
                              TEMP = TEMP + CONJG(AP(K))*X(IX)
  190                     CONTINUE
                      END IF
                      X(JX) = TEMP
                      JX = JX + INCX
                      KK = KK + (N-J+1)
  200             CONTINUE
              END IF
          END IF
      END IF
<span class="comment">*</span><span class="comment">
</span>      RETURN
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     End of <a name="CTPMV.324"></a><a href="ctpmv.f.html#CTPMV.1">CTPMV</a> .
</span><span class="comment">*</span><span class="comment">
</span>      END

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