program write_data_i_arrey
      real x(1000), y(1000)
      character*20 fname
      write(*,*)'Give a file name:(20 chr max)'
      read(*,*)fname

      write(*,*)'How many numbers will you generate? (n<=1000)'
      read(*,*)n

      open(unit=10,file=fname)
      write(10,*)n

      d_theta=3.14/180
      do i=1,n
        x(i)=i*d_theta
        y(i)=sin(x(i))
        write(10,*)x(i),y(i)
      enddo
      close(10)
      write(*,*)'Your',n,' number(s) has been written into ',fname
      end