Go to the documentation of this file.00001 COMPLEX FUNCTION CDOTU(N,CX,INCX,CY,INCY)
00002 * .. Scalar Arguments ..
00003 INTEGER INCX,INCY,N
00004 * ..
00005 * .. Array Arguments ..
00006 COMPLEX CX(*),CY(*)
00007 * ..
00008 *
00009 * Purpose
00010 * =======
00011 *
00012 * CDOTU forms the dot product of two vectors.
00013 *
00014 * Further Details
00015 * ===============
00016 *
00017 * jack dongarra, linpack, 3/11/78.
00018 * modified 12/3/93, array(1) declarations changed to array(*)
00019 *
00020 * =====================================================================
00021 *
00022 * .. Local Scalars ..
00023 COMPLEX CTEMP
00024 INTEGER I,IX,IY
00025 * ..
00026 CTEMP = (0.0,0.0)
00027 CDOTU = (0.0,0.0)
00028 IF (N.LE.0) RETURN
00029 IF (INCX.EQ.1 .AND. INCY.EQ.1) GO TO 20
00030 *
00031 * code for unequal increments or equal increments
00032 * not equal to 1
00033 *
00034 IX = 1
00035 IY = 1
00036 IF (INCX.LT.0) IX = (-N+1)*INCX + 1
00037 IF (INCY.LT.0) IY = (-N+1)*INCY + 1
00038 DO 10 I = 1,N
00039 CTEMP = CTEMP + CX(IX)*CY(IY)
00040 IX = IX + INCX
00041 IY = IY + INCY
00042 10 CONTINUE
00043 CDOTU = CTEMP
00044 RETURN
00045 *
00046 * code for both increments equal to 1
00047 *
00048 20 DO 30 I = 1,N
00049 CTEMP = CTEMP + CX(I)*CY(I)
00050 30 CONTINUE
00051 CDOTU = CTEMP
00052 RETURN
00053 END
