KTH framework for Nek5000 toolboxes; testing version  0.0.1
drot.f
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1  subroutine drot (n,dx,incx,dy,incy,c,s)
2 c
3 c applies a plane rotation.
4 c jack dongarra, linpack, 3/11/78.
5 c modified 12/3/93, array(1) declarations changed to array(*)
6 c
7  double precision dx(*),dy(*),dtemp,c,s
8  integer i,incx,incy,ix,iy,n
9 c
10  if(n.le.0)return
11  if(incx.eq.1.and.incy.eq.1)go to 20
12 c
13 c code for unequal increments or equal increments not equal
14 c to 1
15 c
16  ix = 1
17  iy = 1
18  if(incx.lt.0)ix = (-n+1)*incx + 1
19  if(incy.lt.0)iy = (-n+1)*incy + 1
20  do 10 i = 1,n
21  dtemp = c*dx(ix) + s*dy(iy)
22  dy(iy) = c*dy(iy) - s*dx(ix)
23  dx(ix) = dtemp
24  ix = ix + incx
25  iy = iy + incy
26  10 continue
27  return
28 c
29 c code for both increments equal to 1
30 c
31  20 do 30 i = 1,n
32  dtemp = c*dx(i) + s*dy(i)
33  dy(i) = c*dy(i) - s*dx(i)
34  dx(i) = dtemp
35  30 continue
36  return
37  end
subroutine drot(n, dx, incx, dy, incy, c, s)
Definition: drot.f:2