Error in max(non_high_group) : invalid 'type' (list) of argument

I try the demo in http://bioinfo.life.hust.edu.cn/SEGtool/demo_usage.html. But I got an error.

```
Error in max(non_high_group) : invalid 'type' (list) of argument
In addition: Warning messages:
1: In xtfrm.data.frame(x) : cannot xtfrm data frames
2: In xtfrm.data.frame(x) : cannot xtfrm data frames
3: In xtfrm.data.frame(x) : cannot xtfrm data frames
```