My original data set is
> head(vowel.train, 22)
row.names y x.1 x.2 x.3 x.4 x.5 x.6 x.7 x.8 x.9 x.10
1 1 1 -3.639 0.418 -0.670 1.779 -0.168 1.627 -0.388 0.529 -0.874 -0.814
2 2 2 -3.327 0.496 -0.694 1.365 -0.265 1.933 -0.363 0.510 -0.621 -0.488
3 3 3 -2.120 0.894 -1.576 0.147 -0.707 1.559 -0.579 0.676 -0.809 -0.049
4 4 4 -2.287 1.809 -1.498 1.012 -1.053 1.060 -0.567 0.235 -0.091 -0.795
5 5 5 -2.598 1.938 -0.846 1.062 -1.633 0.764 0.394 -0.150 0.277 -0.396
6 6 6 -2.852 1.914 -0.755 0.825 -1.588 0.855 0.217 -0.246 0.238 -0.365
7 7 7 -3.482 2.524 -0.433 1.048 -1.995 0.902 0.322 0.450 0.377 -0.366
8 8 8 -3.941 2.305 0.124 1.771 -1.815 0.593 -0.435 0.992 0.575 -0.301
9 9 9 -3.860 2.116 -0.939 0.688 -0.675 1.679 -0.512 0.928 -0.167 -0.434
10 10 10 -3.648 1.812 -1.378 1.578 0.065 1.577 -0.466 0.702 0.060 -0.836
11 11 11 -3.032 1.739 -1.141 0.737 -0.834 1.386 -0.575 0.679 -0.018 -0.823
12 12 1 -3.653 0.373 -0.600 1.705 -0.222 1.765 -0.353 0.537 -0.797 -0.813
13 13 2 -3.237 0.436 -0.860 1.363 -0.251 1.915 -0.395 0.751 -0.774 -0.327
14 14 3 -2.135 0.954 -1.632 0.121 -0.704 1.600 -0.628 0.713 -0.903 -0.027
15 15 4 -2.304 1.784 -1.506 0.981 -0.961 0.806 -0.294 -0.002 0.119 -0.760
16 16 5 -2.540 2.144 -1.024 0.933 -1.567 1.024 0.188 -0.047 0.309 -0.633
17 17 6 -2.826 2.003 -0.738 0.801 -1.669 0.939 0.245 -0.257 0.256 -0.458
18 18 7 -3.582 2.374 -0.358 1.162 -1.953 0.621 0.339 0.355 0.415 -0.259
19 19 8 -3.951 2.250 0.127 1.772 -1.906 0.567 -0.432 1.045 0.598 -0.293
20 20 9 -3.783 1.974 -1.200 0.606 -0.650 1.504 -0.134 0.528 0.392 -0.580
21 21 10 -3.673 1.811 -1.405 1.621 0.044 1.572 -0.453 0.745 -0.066 -0.733
22 22 11 -2.946 1.649 -1.167 0.788 -0.909 1.300 -0.562 0.902 -0.070 -0.842
Notice that y variable is my group_id. The id repeats from 1 to 11. And I have hundreds of such observations. Now I want to delete all the observations who have id 5, 8, 9, 10. i.e., I want to from a new data frame that only contains y=1,2,3,4,6,7. How to do?