In-class exercise-3
叫出MASS資料
## 'data.frame': 189 obs. of 10 variables:
## $ low : int 0 0 0 0 0 0 0 0 0 0 ...
## $ age : int 19 33 20 21 18 21 22 17 29 26 ...
## $ lwt : int 182 155 105 108 107 124 118 103 123 113 ...
## $ race : int 2 3 1 1 1 3 1 3 1 1 ...
## $ smoke: int 0 0 1 1 1 0 0 0 1 1 ...
## $ ptl : int 0 0 0 0 0 0 0 0 0 0 ...
## $ ht : int 0 0 0 0 0 0 0 0 0 0 ...
## $ ui : int 1 0 0 1 1 0 0 0 0 0 ...
## $ ftv : int 0 3 1 2 0 0 1 1 1 0 ...
## $ bwt : int 2523 2551 2557 2594 2600 2622 2637 2637 2663 2665 ...檢視資料
## low age lwt race smoke ptl ht ui ftv bwt
## 85 0 19 182 2 0 0 0 1 0 2523
## 86 0 33 155 3 0 0 0 0 3 2551
## 87 0 20 105 1 1 0 0 0 1 2557
## 88 0 21 108 1 1 0 0 1 2 2594
## 89 0 18 107 1 1 0 0 1 0 2600
## 91 0 21 124 3 0 0 0 0 0 2622修改race名稱
## low age lwt race smoke ptl ht ui ftv bwt
## 85 0 19 182 Black 0 0 0 1 0 2523
## 86 0 33 155 Other 0 0 0 0 3 2551
## 87 0 20 105 White 1 0 0 0 1 2557
## 88 0 21 108 White 1 0 0 1 2 2594
## 89 0 18 107 White 1 0 0 1 0 2600
## 91 0 21 124 Other 0 0 0 0 0 2622列出race數量
##
## Black Other White
## 26 67 961. How many black mothers are there in this data frame? 26
2. What does the following R command do? recode
In-class exercise-4
叫出datasets UCBA資料
## , , Dept = A
##
## Gender
## Admit Male Female
## Admitted 512 89
## Rejected 313 19
##
## , , Dept = B
##
## Gender
## Admit Male Female
## Admitted 353 17
## Rejected 207 8
##
## , , Dept = C
##
## Gender
## Admit Male Female
## Admitted 120 202
## Rejected 205 391
##
## , , Dept = D
##
## Gender
## Admit Male Female
## Admitted 138 131
## Rejected 279 244
##
## , , Dept = E
##
## Gender
## Admit Male Female
## Admitted 53 94
## Rejected 138 299
##
## , , Dept = F
##
## Gender
## Admit Male Female
## Admitted 22 24
## Rejected 351 317資料為[Admit, Gender, Dept]
## 'table' num [1:2, 1:2, 1:6] 512 313 89 19 353 207 17 8 120 205 ...
## - attr(*, "dimnames")=List of 3
## ..$ Admit : chr [1:2] "Admitted" "Rejected"
## ..$ Gender: chr [1:2] "Male" "Female"
## ..$ Dept : chr [1:6] "A" "B" "C" "D" ...Gender代號1(男生)的資料
## Dept
## Admit A B C D E F
## Admitted 512 353 120 138 53 22
## Rejected 313 207 205 279 138 351In-class exercise-5
叫出datasets chickwts資料
## weight feed
## 1 179 horsebean
## 2 160 horsebean
## 3 136 horsebean
## 4 227 horsebean
## 5 217 horsebean
## 6 168 horsebean
## 7 108 horsebean
## 8 124 horsebean
## 9 143 horsebean
## 10 140 horsebean
## 11 309 linseed
## 12 229 linseed
## 13 181 linseed
## 14 141 linseed
## 15 260 linseed
## 16 203 linseed
## 17 148 linseed
## 18 169 linseed
## 19 213 linseed
## 20 257 linseed
## 21 244 linseed
## 22 271 linseed
## 23 243 soybean
## 24 230 soybean
## 25 248 soybean
## 26 327 soybean
## 27 329 soybean
## 28 250 soybean
## 29 193 soybean
## 30 271 soybean
## 31 316 soybean
## 32 267 soybean
## 33 199 soybean
## 34 171 soybean
## 35 158 soybean
## 36 248 soybean
## 37 423 sunflower
## 38 340 sunflower
## 39 392 sunflower
## 40 339 sunflower
## 41 341 sunflower
## 42 226 sunflower
## 43 320 sunflower
## 44 295 sunflower
## 45 334 sunflower
## 46 322 sunflower
## 47 297 sunflower
## 48 318 sunflower
## 49 325 meatmeal
## 50 257 meatmeal
## 51 303 meatmeal
## 52 315 meatmeal
## 53 380 meatmeal
## 54 153 meatmeal
## 55 263 meatmeal
## 56 242 meatmeal
## 57 206 meatmeal
## 58 344 meatmeal
## 59 258 meatmeal
## 60 368 casein
## 61 390 casein
## 62 379 casein
## 63 260 casein
## 64 404 casein
## 65 318 casein
## 66 352 casein
## 67 359 casein
## 68 216 casein
## 69 222 casein
## 70 283 casein
## 71 332 caseinVariables為[weight, feed]
## 'data.frame': 71 obs. of 2 variables:
## $ weight: num 179 160 136 227 217 168 108 124 143 140 ...
## $ feed : Factor w/ 6 levels "casein","horsebean",..: 2 2 2 2 2 2 2 2 2 2 ...檢視chickwts[,2] 的呈現方式和class & type
## [1] horsebean horsebean horsebean horsebean horsebean horsebean horsebean
## [8] horsebean horsebean horsebean linseed linseed linseed linseed
## [15] linseed linseed linseed linseed linseed linseed linseed
## [22] linseed soybean soybean soybean soybean soybean soybean
## [29] soybean soybean soybean soybean soybean soybean soybean
## [36] soybean sunflower sunflower sunflower sunflower sunflower sunflower
## [43] sunflower sunflower sunflower sunflower sunflower sunflower meatmeal
## [50] meatmeal meatmeal meatmeal meatmeal meatmeal meatmeal meatmeal
## [57] meatmeal meatmeal meatmeal casein casein casein casein
## [64] casein casein casein casein casein casein casein
## [71] casein
## Levels: casein horsebean linseed meatmeal soybean sunflower## [1] "factor"## [1] "integer"檢視chickwts[“feed”] 的呈現方式和class & type
## feed
## 1 horsebean
## 2 horsebean
## 3 horsebean
## 4 horsebean
## 5 horsebean
## 6 horsebean
## 7 horsebean
## 8 horsebean
## 9 horsebean
## 10 horsebean
## 11 linseed
## 12 linseed
## 13 linseed
## 14 linseed
## 15 linseed
## 16 linseed
## 17 linseed
## 18 linseed
## 19 linseed
## 20 linseed
## 21 linseed
## 22 linseed
## 23 soybean
## 24 soybean
## 25 soybean
## 26 soybean
## 27 soybean
## 28 soybean
## 29 soybean
## 30 soybean
## 31 soybean
## 32 soybean
## 33 soybean
## 34 soybean
## 35 soybean
## 36 soybean
## 37 sunflower
## 38 sunflower
## 39 sunflower
## 40 sunflower
## 41 sunflower
## 42 sunflower
## 43 sunflower
## 44 sunflower
## 45 sunflower
## 46 sunflower
## 47 sunflower
## 48 sunflower
## 49 meatmeal
## 50 meatmeal
## 51 meatmeal
## 52 meatmeal
## 53 meatmeal
## 54 meatmeal
## 55 meatmeal
## 56 meatmeal
## 57 meatmeal
## 58 meatmeal
## 59 meatmeal
## 60 casein
## 61 casein
## 62 casein
## 63 casein
## 64 casein
## 65 casein
## 66 casein
## 67 casein
## 68 casein
## 69 casein
## 70 casein
## 71 casein## [1] "data.frame"## [1] "list"The class of chickwts[,2] is “factor”, the type is “integer”
The class of chickwts[“feed”] is “data.frame”, the type is “list”
In-class exercise-6
## starting httpd help server ... done了解MASS的第92個項目的資訊：menarche"