data<-InsectSprays
palette<-c("indianred2","khaki","lavenderblush2","lemonchiffon4","lightcyan1","lightgoldenrod4")

### method using aggregate
dead<-aggregate(count ~ spray,data=InsectSprays,sum)
pie(dead$count,labels=dead$spray,col=palette)

### method using a loop
data<-InsectSprays
palette<-c("slategray2","salmon2","seagreen4","mistyrose3","peachpuff","navajowhite4")

insecticide<-levels(as.factor(data$spray))
dead<-NULL
for(i in 1:length(insecticide)){
rows<-which(data$spray==insecticide[i])
dead<-c(dead,sum(data[rows,1]))
}
pie(dead,labels=insecticide,col=palette)


### method using tapply
data<-InsectSprays
palette<-c("cadetblue3","chocolate1","coral4","darkgoldenrod2","deepskyblue1","gainsboro")
dead<-tapply(InsectSprays$count,InsectSprays$spray,sum)
pie(dead,labels=levels(as.factor(InsectSprays$spray)),init.angle=180,col=palette)


### method using circlise
install.packages("circlize")
library(circlize)
dead<-aggregate(count ~ spray,data=InsectSprays,sum)

total<-sum(dead$count)
m<-cumsum(dead$count)
n<-nrow(dead)
x<-360*m/total
x<-c(0,x)
plot(NULL,xlim=c(-max(m),max(m)),ylim=c(-max(m),max(m)),axes=F,ann=F, type="n",xlab="",ylab="") # set up a blank plot area with size based on max mass (log base 2)
for (i in 1:n){
draw.sector(start.degree=x[i],end.degree=x[i+1], clock.wise=FALSE,rou1=100,rou2=650,col=palette[i],border = "black",lwd = 1,lty =0)
}
angles<-NULL
for(i in 1:n) angles<-c(angles,0.5*(x[i+1]-x[i]))
letter_angle<-angles+x[1:6]
xval<-400*cos(letter_angle*pi/180)
yval<-400*sin(letter_angle*pi/180)
text(xval,yval,as.character(dead$spray),cex=3)