Incorrect display of multiple boxplot in one graph

Question

I expected to see all boxplots will be overlayed at 25, 85 and 125 on x axis but they were not. Please run the code to replicate, I can't attach the image. Thank you so much.

library("ggplot2")
library("plyr")

df<-data.frame(T = c(25, 25, 25, 25, 25, 85, 85, 85, 125, 125, 125), V =c(1.03, 1.06, 1.1,1.08,1.87,1.56,1.75,1.82, 1.85, 1.90), type=c(2,2,2,2,2,2,2))
df1<-data.frame(T = c(25, 25,25,85, 85, 85, 85, 125, 125,125), V =c(1.13, 1.24,1.3,1.17, 1.66,1.76,1.89, 1.90, 1.95,1.97), type=c(5,5,5,5,5,5,5))
df2<-data.frame(T = c(25, 25, 25, 85, 85,85,125, 125,125), V =c(1.03, 1.06, 1.56,1.75,1.68,1.71,1.82, 1.85,1.88), type=c(7,7,7,7,7,7))

main <- rbind(df,df1,df2)
main$type <- as.factor(main$type)

main <- transform(main, type = revalue(type,c("2"="type2", "5"="type5", "7" = "type7")))

main$T <- as.factor(main$T)
ggplot(main, aes(T, V))+geom_boxplot(width=0.5/length(unique(main$type)),aes(color=type),size=.3)

Answer 1

First of all you need to make some changes to your dfs. a) Not all variables have the same length. b) Do not name a variable as T, it might confuse R with Boolean TRUE.

So maybe what you want is the following?

df<-data.frame(U = c(25, 25, 25, 25, 25, 85, 85, 85, 125, 125), 
               V =c(1.03, 1.06, 1.1,1.08,1.87,1.56,1.75,1.82, 1.85, 1.90), type=c(2,2,2,2,2,2,2,2,2,2)) 

df1<-data.frame(U = c(25, 25,25,85, 85, 85, 85, 125, 125,125), 
                V =c(1.13, 1.24,1.3,1.17, 1.66,1.76,1.89, 1.90, 1.95,1.97), type=c(5,5,5,5,5,5,5,5,5,5)) 

df2<-data.frame(U = c(25, 25, 25, 85, 85,85,125, 125,125), 
                V =c(1.03, 1.06, 1.56,1.75,1.68,1.71,1.82, 1.85,1.88), type=c(7,7,7,7,7,7,7,7,7))

main <- rbind(df,df1,df2) 
main$type <- as.factor(main$type)

main <- transform(main, type = revalue(type,c("2"="type2", "5"="type5", "7" = "type7")))

main$U <- as.factor(main$U) 

ggplot(main, aes(U, V,color=type))+geom_boxplot(width=0.5/length(unique(main$type)),size=.3,position="identity")