我的数据框看起来像：
> str(b)
'data.frame': 2720 obs. of 3 variables:
$ Hospital.Name: chr "SOUTHEAST ALABAMA MEDICAL CENTER" "MARSHALL MEDICAL CENTER SOUTH" "ELIZA COFFEE MEMORIAL HOSPITAL" "ST VINCENT'S EAST" ...
$ State : chr "AL" "AL" "AL" "AL" ...
$ heart attack : num 14.3 18.5 18.1 17.7 18 15.9 19.6 17.3 17.8 17.5 ...
我想按状态对其进行分组，按状态和心脏病发作对它们进行排序，然后添加一列返回每个组内的行号。理想的结果如下：
# A tibble: 2,720 x 4
# Groups: State [54]
Hospital.Name State `heart attack` rank
<chr> <chr> <dbl> <int>
1 PROVIDENCE ALASKA MEDICAL CENTER AK 13.4 …我想通过 ggplot 2 从向量绘制直方图。数据集是数据集包中的河流
rivers
[1] 735 320 325 392 524 450 1459 135 465 600 330 336 280 315 870 906 202 329
[19] 290 1000 600 505 1450 840 1243 890 350 407 286 280 525 720 390 250 327 230
[37] 265 850 210 630 260 230 360 730 600 306 390 420 291 710 340 217 281 352
[55] 259 250 470 680 570 350 300 560 900 625 332 2348 1171 3710 2315 2533 780 …