root / src / blas / zdscal.f @ 5
Historique | Voir | Annoter | Télécharger (902 octet)
| 1 |
SUBROUTINE ZDSCAL(N,DA,ZX,INCX) |
|---|---|
| 2 |
* .. Scalar Arguments .. |
| 3 |
DOUBLE PRECISION DA |
| 4 |
INTEGER INCX,N |
| 5 |
* .. |
| 6 |
* .. Array Arguments .. |
| 7 |
DOUBLE COMPLEX ZX(*) |
| 8 |
* .. |
| 9 |
* |
| 10 |
* Purpose |
| 11 |
* ======= |
| 12 |
* |
| 13 |
* scales a vector by a constant. |
| 14 |
* jack dongarra, 3/11/78. |
| 15 |
* modified 3/93 to return if incx .le. 0. |
| 16 |
* modified 12/3/93, array(1) declarations changed to array(*) |
| 17 |
* |
| 18 |
* |
| 19 |
* .. Local Scalars .. |
| 20 |
INTEGER I,IX |
| 21 |
* .. |
| 22 |
* .. Intrinsic Functions .. |
| 23 |
INTRINSIC DCMPLX |
| 24 |
* .. |
| 25 |
IF (N.LE.0 .OR. INCX.LE.0) RETURN |
| 26 |
IF (INCX.EQ.1) GO TO 20 |
| 27 |
* |
| 28 |
* code for increment not equal to 1 |
| 29 |
* |
| 30 |
IX = 1 |
| 31 |
DO 10 I = 1,N |
| 32 |
ZX(IX) = DCMPLX(DA,0.0d0)*ZX(IX) |
| 33 |
IX = IX + INCX |
| 34 |
10 CONTINUE |
| 35 |
RETURN |
| 36 |
* |
| 37 |
* code for increment equal to 1 |
| 38 |
* |
| 39 |
20 DO 30 I = 1,N |
| 40 |
ZX(I) = DCMPLX(DA,0.0d0)*ZX(I) |
| 41 |
30 CONTINUE |
| 42 |
RETURN |
| 43 |
END |