data<-read.csv("malaria.csv",as.is = T)
o=table(data$occupation) 
#look the occupation column
o
## 
##     chain sawyer            child           driver           farmer 
##               18              171               14              483 
##   flour producer general services     health agent       management 
##                9               16               26               17 
##           others          retired    stays at home          student 
##               31               13              209              446 
##          teacher           trader 
##               43               12
barplot(o) 

## it does not look very nice
name<-names(o) 
# we want each bar has a corresponding text under it
barplot(o, main="Occupation",names.arg = name, las=2, col="white",ylab="Number of people")

data<-read.csv("malaria.csv",as.is = T)
par(mfrow=c(2,2),mar=c(7,2,1,1),oma=c(1,4,4,1))
#mfrow show up multiple graphs in one plot; 
#mar and oma can regulate plots distance
#Besides, we want the x-axis be "female" and "male" rather than "0" and "1"
data$gender1<-"male" ## make a new column by dollor sign $
vector<-data$gender==0  
# Create a logic vector, the results are either "FALSE" OR "TRUE"
# "==" means if equal; 0 result in TRUE
data[vector,'gender1']<-"female" 
boxplot(age~gender1,data=data,ylab='')
boxplot(age~occupation,data=data,las=2,ylab='') 
#las=2 makes x-axis labels be displayed vertically
boxplot(time_acrel~gender1,data=data,ylab='')
boxplot(time_acrel~occupation,data=data,las=2,ylab='') 
# las=2 makes x-axis labels be displayed vertically
#Notice age is y-axis here. boxplot using "~", a little bit special

# Now, we want to add a text at the left for both the two plots
mtext(side=2,at=c(0.4,0.9),c('Time in Acrelandia(Years)','Age(years)'),outer=T,line = 2)
# Now, we want to add a text at the top
mtext(side=3,at=c(0.3,0.75),c('By gender','By occupation'),outer=T,line = 2)