1: DOUBLE COMPLEX FUNCTION ZDOTU(N,ZX,INCX,ZY,INCY)
2: * .. Scalar Arguments ..
3: INTEGER INCX,INCY,N
4: * ..
5: * .. Array Arguments ..
6: DOUBLE COMPLEX ZX(*),ZY(*)
7: * ..
8: *
9: * Purpose
10: * =======
11: *
12: * ZDOTU forms the dot product of two vectors.
13: *
14: * Further Details
15: * ===============
16: *
17: * jack dongarra, 3/11/78.
18: * modified 12/3/93, array(1) declarations changed to array(*)
19: *
20: * =====================================================================
21: *
22: * .. Local Scalars ..
23: DOUBLE COMPLEX ZTEMP
24: INTEGER I,IX,IY
25: * ..
26: ZTEMP = (0.0d0,0.0d0)
27: ZDOTU = (0.0d0,0.0d0)
28: IF (N.LE.0) RETURN
29: IF (INCX.EQ.1 .AND. INCY.EQ.1) GO TO 20
30: *
31: * code for unequal increments or equal increments
32: * not equal to 1
33: *
34: IX = 1
35: IY = 1
36: IF (INCX.LT.0) IX = (-N+1)*INCX + 1
37: IF (INCY.LT.0) IY = (-N+1)*INCY + 1
38: DO 10 I = 1,N
39: ZTEMP = ZTEMP + ZX(IX)*ZY(IY)
40: IX = IX + INCX
41: IY = IY + INCY
42: 10 CONTINUE
43: ZDOTU = ZTEMP
44: RETURN
45: *
46: * code for both increments equal to 1
47: *
48: 20 DO 30 I = 1,N
49: ZTEMP = ZTEMP + ZX(I)*ZY(I)
50: 30 CONTINUE
51: ZDOTU = ZTEMP
52: RETURN
53: END
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