An examble with RMarkdown

Khoa hoc R ngay 10-05-2025

Đọc dữ liệu

Đọc dữ liệu vào Birthwt

bw=read.csv("D:\\R\\DỮ LIỆU THỰC HÀNH (TS Thạch gửi)\\birthwt.csv")

###Kiem tra hang cot

 dim(bw)

## [1] 189  11

###kiem tra 10 hang cuoi

tail(bw,10)

##     id low age lwt race smoke ptl ht ui ftv  bwt
## 180 71   1  17 120    2     0   0  0  0   2 2438
## 181 75   1  26 154    3     0   1  1  0   1 2442
## 182 76   1  20 105    3     0   0  0  0   3 2450
## 183 77   1  26 190    1     1   0  0  0   0 2466
## 184 78   1  14 101    3     1   1  0  0   0 2466
## 185 79   1  28  95    1     1   0  0  0   2 2466
## 186 81   1  14 100    3     0   0  0  0   2 2495
## 187 82   1  23  94    3     1   0  0  0   0 2495
## 188 83   1  17 142    2     0   0  1  0   0 2495
## 189 84   1  21 130    1     1   0  1  0   3 2495

###kiem tra 15 hang dau

head(bw,15)

##     id low age lwt race smoke ptl ht ui ftv  bwt
## 1   85   0  19 182    2     0   0  0  1   0 2523
## 2   86   0  33 155    3     0   0  0  0   3 2551
## 3   87   0  20 105    1     1   0  0  0   1 2557
## 4   88   0  21 108    1     1   0  0  1   2 2594
## 5   89   0  18 107    1     1   0  0  1   0 2600
## 6   91   0  21 124    3     0   0  0  0   0 2622
## 7   92   0  22 118    1     0   0  0  0   1 2637
## 8   93   0  17 103    3     0   0  0  0   1 2637
## 9   94   0  29 123    1     1   0  0  0   1 2663
## 10  95   0  26 113    1     1   0  0  0   0 2665
## 11  96   0  19  95    3     0   0  0  0   0 2722
## 12  97   0  19 150    3     0   0  0  0   1 2733
## 13  98   0  22  95    3     0   0  1  0   0 2751
## 14  99   0  30 107    3     0   1  0  1   2 2750
## 15 100   0  18 100    1     1   0  0  0   0 2769

viec 5; Tạo biến số

5.1 Tạo biến mw

bw$mwt2=bw$lwt*0.45

5.2 Kha bao mau

bw$ethnicity[bw$race==1]="white"
bw$ethnicity[bw$race==2]="black"
bw$ethnicity[bw$race==3]="other"
table(bw$ethnicity,bw$race)

##        
##          1  2  3
##   black  0 26  0
##   other  0  0 67
##   white 96  0  0

5.3 tao tap tin bw1

bw1=bw[,c("id","low","bwt")]

5.4 tao tap tin bw3

bw1=bw[,c("id","low","bwt")]

5.5 Tao bw4

bw4=subset(bw,low==1& smoke==1)

5.6

bw2ethnicity <- factor(bw$race, levels = c(1, 2, 3), labels = c("White", "Black", "Other"))