[R] problem: the id of the data set

[周 可卫]

I got the dataset after merge two old one .The  id of the column isn’t  just the number of the column.So when I identify some obs,I got the figure 28000(though my obs is only 6000).So it causes the trouble to remove these obs in the dataset.I wander how to make the id of the merged dataset in a right order.Or what could I do when I did identify the id of the outliner(but not the number of the column it belongs to ) when I need to remove those obs.
Thanks for your time.