program main implicit none real*8, allocatable :: r(:), theta(:), x(:,:) real*8 time integer*8 time0, time1, dtime integer i, j, n c n = 10000 c Initialization allocate(r(n), theta(n), x(n,n)) do i=1,n r(i) = rand() theta(i) = rand() end do c Start time call system_clock(time0) c Main calculation do j=1,n c do i=1,n x(i,j) = r(j) * cos(theta(i)) end do end do c Finish time call system_clock(time1, dtime) c Output time time = 1d0*(time1-time0)/dtime write(*,"(a7,f16.7)")"Time = ",time deallocate(r, theta, x) end program