Source module last modified on Thu, 2 Jul 1998, 23:17;
HTML image of Fortran source automatically generated by
for2html on Sun, 23 Jun 2002, 15:10.
subroutine zdrot (n,zx,incx,zy,incy,c,s)
#
# applies a plane rotation, where the cos and sin (c and s) are
# double precision and the vectors zx and zy are double complex.
# jack dongarra, linpack, 3/11/78.
#
double complex zx(1),zy(1),ztemp
double precision c,s
integer i,incx,incy,ix,iy,n
#
if(n<=0)return
if(incx==1&&incy==1)go to 20
#
# code for unequal increments or equal increments not equal
# to 1
#
ix = 1
iy = 1
if(incx<0)ix = (-n+1)*incx + 1
if(incy<0)iy = (-n+1)*incy + 1
do 10 i = 1,n
ztemp = c*zx(ix) + s*zy(iy)
zy(iy) = c*zy(iy) - s*zx(ix)
zx(ix) = ztemp
ix = ix + incx
iy = iy + incy
10 continue
return
#
# code for both increments equal to 1
#
20 do 30 i = 1,n
ztemp = c*zx(i) + s*zy(i)
zy(i) = c*zy(i) - s*zx(i)
zx(i) = ztemp
30 continue
return
end