#Viec2 Cai dat goi lenh
#Viec3:Nhap du lieu
ob = read.csv("D:\\2025-10-Tap huan_Phan tich du lieu va cong bo Quoc te danh cho giang vien\\Obesity data.csv")
#Viec4:
# Kiểm tra số lượng quan sát (số dòng) và biến số (số cột)
dim(ob)## [1] 1217 13# Số quan sát (dòng)
nrow(ob)## [1] 1217# Số biến số (cột)
ncol(ob)## [1] 13#6 quan sat dau tien
head(ob)## id gender height weight bmi age WBBMC wbbmd fat lean pcfat hypertension
## 1 1 F 150 49 21.8 53 1312 0.88 17802 28600 37.3 0
## 2 2 M 165 52 19.1 65 1309 0.84 8381 40229 16.8 1
## 3 3 F 157 57 23.1 64 1230 0.84 19221 36057 34.0 1
## 4 4 F 156 53 21.8 56 1171 0.80 17472 33094 33.8 1
## 5 5 M 160 51 19.9 54 1681 0.98 7336 40621 14.8 0
## 6 6 F 153 47 20.1 52 1358 0.91 14904 30068 32.2 1
## diabetes
## 1 1
## 2 0
## 3 0
## 4 0
## 5 0
## 6 0#6 quan sat cuoi cung
tail(ob)## id gender height weight bmi age WBBMC wbbmd fat lean pcfat
## 1212 1222 F 153 50 21.4 59 1309 0.87 18328 29147 37.6
## 1213 1223 F 150 44 19.6 44 1474 0.95 12906 28534 30.1
## 1214 1224 F 148 51 23.3 58 1522 0.97 14938 33931 29.6
## 1215 1225 F 149 50 22.5 57 1409 0.93 16777 30598 34.4
## 1216 1226 F 144 49 23.6 67 1266 0.90 20094 27272 41.3
## 1217 1227 F 141 45 22.6 58 1228 0.91 14567 28111 33.2
## hypertension diabetes
## 1212 1 0
## 1213 0 1
## 1214 0 0
## 1215 1 0
## 1216 1 0
## 1217 0 0#Tom tat
summary(ob)## id gender height weight
## Min. : 1.0 Length:1217 Min. :136.0 Min. :34.00
## 1st Qu.: 309.0 Class :character 1st Qu.:151.0 1st Qu.:49.00
## Median : 615.0 Mode :character Median :155.0 Median :54.00
## Mean : 614.5 Mean :156.7 Mean :55.14
## 3rd Qu.: 921.0 3rd Qu.:162.0 3rd Qu.:61.00
## Max. :1227.0 Max. :185.0 Max. :95.00
## bmi age WBBMC wbbmd fat
## Min. :14.5 Min. :13.00 Min. : 695 Min. :0.650 Min. : 4277
## 1st Qu.:20.2 1st Qu.:35.00 1st Qu.:1481 1st Qu.:0.930 1st Qu.:13768
## Median :22.2 Median :48.00 Median :1707 Median :1.010 Median :16955
## Mean :22.4 Mean :47.15 Mean :1725 Mean :1.009 Mean :17288
## 3rd Qu.:24.3 3rd Qu.:58.00 3rd Qu.:1945 3rd Qu.:1.090 3rd Qu.:20325
## Max. :37.1 Max. :88.00 Max. :3040 Max. :1.350 Max. :40825
## lean pcfat hypertension diabetes
## Min. :19136 Min. : 9.2 Min. :0.000 Min. :0.0000
## 1st Qu.:30325 1st Qu.:27.0 1st Qu.:0.000 1st Qu.:0.0000
## Median :33577 Median :32.4 Median :1.000 Median :0.0000
## Mean :35463 Mean :31.6 Mean :0.507 Mean :0.1109
## 3rd Qu.:39761 3rd Qu.:36.8 3rd Qu.:1.000 3rd Qu.:0.0000
## Max. :63059 Max. :48.4 Max. :1.000 Max. :1.0000#Viec5: Bien tap du lieu
ob$sex <- ifelse(ob$gender == "F", 1, 0)
ob$obese <- cut(ob$bmi,
breaks = c(-Inf, 18.5, 25.0, 30.0, Inf),
labels = c("Underweight", "Normal", "Overweight", "Obese"),
right = FALSE)
names(ob)## [1] "id" "gender" "height" "weight" "bmi"
## [6] "age" "WBBMC" "wbbmd" "fat" "lean"
## [11] "pcfat" "hypertension" "diabetes" "sex" "obese"dim(ob) # Xem số dòng và cột## [1] 1217 15head(ob$weight)## [1] 49 52 57 53 51 47head(ob$FatPercent)## NULLob$fat.kg <- ob$weight * ob$pcfat / 100
ob$lean.kg <- ob$weight - ob$fat.kg
men.overweight <- subset(ob, gender == "M" & bmi >= 25.0)
dim(men.overweight)## [1] 85 17Demo <- ob[, c("id", "age", "gender", "height", "weight", "pcfat")]
#Viec6:GHilai lenh va chia se