1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
|
SUBROUTINE CAXPY(N,CA,CX,INCX,CY,INCY)
* .. Scalar Arguments ..
COMPLEX CA
INTEGER INCX,INCY,N
* ..
* .. Array Arguments ..
COMPLEX CX(*),CY(*)
* ..
*
* Purpose
* =======
*
* CAXPY constant times a vector plus a vector.
*
* Further Details
* ===============
*
* jack dongarra, linpack, 3/11/78.
* modified 12/3/93, array(1) declarations changed to array(*)
*
* =====================================================================
*
* .. Local Scalars ..
INTEGER I,IX,IY
* ..
* .. External Functions ..
REAL SCABS1
EXTERNAL SCABS1
* ..
IF (N.LE.0) RETURN
IF (SCABS1(CA).EQ.0.0E+0) RETURN
IF (INCX.EQ.1 .AND. INCY.EQ.1) THEN
*
* code for both increments equal to 1
*
DO I = 1,N
CY(I) = CY(I) + CA*CX(I)
END DO
ELSE
*
* code for unequal increments or equal increments
* not equal to 1
*
IX = 1
IY = 1
IF (INCX.LT.0) IX = (-N+1)*INCX + 1
IF (INCY.LT.0) IY = (-N+1)*INCY + 1
DO I = 1,N
CY(IY) = CY(IY) + CA*CX(IX)
IX = IX + INCX
IY = IY + INCY
END DO
END IF
*
RETURN
END
|
