删除观察

Question

这是非常基本的，但我一直坚持这一段时间了。

我想从数据集hitters.txt删除观察-Steven Sax：

> dput(hitters[280:290,]) 
structure(list(AtBat = c(439L, 453L, 528L, 633L, 16L, 562L, 281L, 
593L, 687L, 368L, 263L), Hits = c(96L, 103L, 122L, 210L, 2L, 
169L, 76L, 152L, 213L, 103L, 70L), HmRun = c(0L, 8L, 1L, 6L, 
0L, 17L, 3L, 23L, 10L, 3L, 1L), Runs = c(44L, 53L, 67L, 91L, 
1L, 88L, 42L, 69L, 91L, 48L, 26L), RBI = c(36L, 33L, 45L, 56L, 
0L, 73L, 25L, 75L, 65L, 28L, 23L), Walks = c(65L, 52L, 51L, 59L, 
0L, 53L, 20L, 53L, 27L, 54L, 30L), Years = c(4L, 2L, 4L, 6L, 
2L, 8L, 8L, 6L, 4L, 8L, 4L), CAtBat = c(711L, 507L, 1716L, 3070L, 
28L, 3181L, 2658L, 2765L, 1518L, 1897L, 888L), CHits = c(148L, 
123L, 403L, 872L, 4L, 841L, 657L, 686L, 448L, 493L, 220L), CHmRun = c(1L, 
8L, 12L, 19L, 0L, 61L, 48L, 133L, 15L, 9L, 9L), CRuns = c(68L, 
63L, 211L, 420L, 1L, 450L, 324L, 369L, 196L, 207L, 83L), CRBI = c(56L, 
39L, 146L, 230L, 0L, 342L, 300L, 384L, 137L, 162L, 82L), CWalks = c(99L, 
58L, 155L, 274L, 0L, 373L, 179L, 321L, 89L, 198L, 86L), League = structure(c(2L, 
1L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 2L, 2L), .Label = c("A", "N"), class = "factor"), 
    Division = structure(c(1L, 2L, 2L, 2L, 1L, 1L, 1L, 2L, 1L, 
    2L, 1L), .Label = c("E", "W"), class = "factor"), PutOuts = c(229L, 
    289L, 209L, 367L, 247L, 351L, 106L, 315L, 294L, 209L, 81L 
    ), Assists = c(406L, 407L, 372L, 432L, 4L, 442L, 144L, 10L, 
    445L, 246L, 147L), Errors = c(22L, 6L, 17L, 16L, 8L, 17L, 
    7L, 6L, 13L, 3L, 4L), Salary = c(150, 105, 350, 90, NA, 530, 
    341.667, 940, 350, 326.667, 250), NewLeague = structure(c(2L, 
    1L, 1L, 2L, 1L, 1L, 1L, 1L, 1L, 2L, 2L), .Label = c("A", 
    "N"), class = "factor")), .Names = c("AtBat", "Hits", "HmRun", 
"Runs", "RBI", "Walks", "Years", "CAtBat", "CHits", "CHmRun", 
"CRuns", "CRBI", "CWalks", "League", "Division", "PutOuts", "Assists", 
"Errors", "Salary", "NewLeague"), row.names = c("-Steve Jeltz", 
"-Steve Lombardozzi", "-Spike Owen", "-Steve Sax", "-Tony Armas", 
"-Tony Bernazard", "-Tom Brookens", "-Tom Brunansky", "-Tony Fernandez", 
"-Tim Flannery", "-Tom Foley"), class = "data.frame") 

如果我知道我会用第一列的名称：

hitters <- hitters[!hitters$Colname == "-Steve Sax",] 

或

hitters <- hitters[hitters$AtBat != "-Steve Sax", ] 

但我不k现在第一列的名称：

。我曾尝试：read.table("hitters.txt", head = F) `和

read.table("hitters.txt", head = F) 

我的问题是：

1. 我怎样才能取出观察？
2. 为什么head = T没有用？

Answer 1

第一个“列”表示行名称（这不是数据集中的实际列，而是出现在输出中）。您可以用功能rownames访问行名称：

hitters[!rownames(hitters) %in% '-Steve Sax', ] 

将提取从数据集中观察。

输出：

    AtBat Hits HmRun Runs RBI Walks Years CAtBat CHits CHmRun CRuns 
-Steve Jeltz   439 96  0 44 36 65  4 711 148  1 68 
-Steve Lombardozzi 453 103  8 53 33 52  2 507 123  8 63 
-Spike Owen   528 122  1 67 45 51  4 1716 403  12 211 
-Tony Armas   16 2  0 1 0  0  2  28  4  0  1 
-Tony Bernazard  562 169 17 88 73 53  8 3181 841  61 450 
-Tom Brookens  281 76  3 42 25 20  8 2658 657  48 324 
-Tom Brunansky  593 152 23 69 75 53  6 2765 686 133 369 
-Tony Fernandez  687 213 10 91 65 27  4 1518 448  15 196 
-Tim Flannery  368 103  3 48 28 54  8 1897 493  9 207 
-Tom Foley   263 70  1 26 23 30  4 888 220  9 83