用以下程序计算tent map时间序列，结果大家可以看到迭代十几步之后精度的误差就这么大，完全偏离预期结果，不知道要怎么办，求解！！！！
program tent 
implicit none
   parameter N=1000
   integer :: i
   double precision :: x(N) 
   open(10,file='data.txt')
    x(1)=0.2_8    
    do i=2,N
      x(i)=1.0-2.0*abs(x(i-1)-0.5)
    end do
    do i=1,N
      write(10,*)i,x(i)
    enddo
end

结果：
           1  0.200000000000000     
           2  0.400000000000000     
           3  0.800000000000000     
           4  0.400000000000000     
           5  0.800000000000000     
           6  0.400000000000000     
           7  0.800000000000001     
           8  0.399999999999999     
           9  0.799999999999997     
          10  0.400000000000006     
          11  0.800000000000011     
          12  0.399999999999977     
          13  0.799999999999955     
          14  0.400000000000091     
          15  0.800000000000182
PS：编译环境用的是CVF6.6