Mercurial > octave-nkf
annotate libcruft/blas/zdrot.f @ 7575:d20a2f261306
use * instead of 1 for assumed-size fortran arrays
| author | John W. Eaton <jwe@octave.org> |
|---|---|
| date | Mon, 10 Mar 2008 13:30:01 -0400 |
| parents | 30c606bec7a8 |
| children |
| rev | line source |
|---|---|
| 2329 | 1 subroutine zdrot (n,zx,incx,zy,incy,c,s) |
| 2 c | |
| 3 c applies a plane rotation, where the cos and sin (c and s) are | |
| 4 c double precision and the vectors zx and zy are double complex. | |
| 5 c jack dongarra, linpack, 3/11/78. | |
| 6 c | |
|
7575
d20a2f261306
use * instead of 1 for assumed-size fortran arrays
John W. Eaton <jwe@octave.org>
parents:
2329
diff
changeset
|
7 double complex zx(*),zy(*),ztemp |
| 2329 | 8 double precision c,s |
| 9 integer i,incx,incy,ix,iy,n | |
| 10 c | |
| 11 if(n.le.0)return | |
| 12 if(incx.eq.1.and.incy.eq.1)go to 20 | |
| 13 c | |
| 14 c code for unequal increments or equal increments not equal | |
| 15 c to 1 | |
| 16 c | |
| 17 ix = 1 | |
| 18 iy = 1 | |
| 19 if(incx.lt.0)ix = (-n+1)*incx + 1 | |
| 20 if(incy.lt.0)iy = (-n+1)*incy + 1 | |
| 21 do 10 i = 1,n | |
| 22 ztemp = c*zx(ix) + s*zy(iy) | |
| 23 zy(iy) = c*zy(iy) - s*zx(ix) | |
| 24 zx(ix) = ztemp | |
| 25 ix = ix + incx | |
| 26 iy = iy + incy | |
| 27 10 continue | |
| 28 return | |
| 29 c | |
| 30 c code for both increments equal to 1 | |
| 31 c | |
| 32 20 do 30 i = 1,n | |
| 33 ztemp = c*zx(i) + s*zy(i) | |
| 34 zy(i) = c*zy(i) - s*zx(i) | |
| 35 zx(i) = ztemp | |
| 36 30 continue | |
| 37 return | |
| 38 end |