double complex function zdotu(n,zx,incx,zy,incy) c c forms the dot product of two vectors. c jack dongarra, 3/11/78. c modified 12/3/93, array(1) declarations changed to array(*) c double complex zx(*),zy(*),ztemp integer i,incx,incy,ix,iy,n ztemp = (0.0d0,0.0d0) zdotu = (0.0d0,0.0d0) if(n.le.0)return if(incx.eq.1.and.incy.eq.1)go to 20 c c code for unequal increments or equal increments c not equal to 1 c ix = 1 iy = 1 if(incx.lt.0)ix = (-n+1)*incx + 1 if(incy.lt.0)iy = (-n+1)*incy + 1 do 10 i = 1,n ztemp = ztemp + zx(ix)*zy(iy) ix = ix + incx iy = iy + incy 10 continue zdotu = ztemp return c c code for both increments equal to 1 c 20 do 30 i = 1,n ztemp = ztemp + zx(i)*zy(i) 30 continue zdotu = ztemp return end