Scales a vector by a constant.
subroutine zscal(n,za,zx,incx)
c
scales a vector by a constant.
c
jack dongarra, 3/11/78.
c
modified to correct problem with negative increment, 8/21/90.
double
complex za,zx(1)
integer
i,incx,ix,n
if(n.le.0)return
if(incx.eq.1)go
to 20
c
code for increment not equal to 1
ix
= 1
if(incx.lt.0)ix
= (-n+1)*incx + 1
do
10 i = 1,n
zx(ix)
= za*zx(ix)
ix
= ix + incx
10
continue
return
c
code for increment equal to 1
20
do 30 i = 1,n
zx(i)
= za*zx(i)
30
continue
return
end