R中的多个变量箱形图

Question

I am new to R and statistical analysis as a whole. I am currently working with a data set that includes age and memory as well as concentrations of specific compounds. My data was obtained from a csv file by using read.csv.

Currently I can display a box plot for one age group and one protein by using

boxplot(data$compound_A[data$Age.Code==3]~q$Memory.Code[q$Age.Code==3])

I encounter a problem when I want to look at two age groups. I have tried

boxplot(data$compound_A[data$Age.Code==3]~q$Memory.Code[data$Age.Code==3],
data$compound_A[data$Age.Code==2]~q$Memory.Code[q$Age.Code==2])

and a few permutations of it such as:

boxplot(data$compound_A[data$Age.Code==3]~q$Memory.Code[data$Age.Code==3],data,
data$compound_A[data$Age.Code==2]~q$Memory.Code[q$Age.Code==2],data)

Unfortunately none of these approaches has worked. Any help would be appreciated!

Thank you!

As suggested here is some of my data using the dput option

structure(list(ID = c(635L, 637L, 638L, 639L, 641L, 642L, 644L, 
646L, 647L, 649L, 652L, 676L, 677L, 678L, 679L, 682L, 684L, 686L, 
688L, 692L, 693L, 715L, 716L, 717L, 718L, 719L), Age.Code = c(3L, 
3L, 3L, 3L, 3L, 3L, 3L, 3L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 
3L, 3L, 3L, 3L, 2L, 2L, 2L, 2L, 2L), Memory.Code = c(2L, 2L, 
2L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 1L, 1L, 2L, 1L, 
1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L), Compound_A = c(NA, 0, 93.25, 
42.79, 148.94, 41.98, 38.99, 0, 0, 42.79, 41.98, 0, 27.38, 76.51, 
121.6, 0, 153.69, 68.6, 189.15, NA, 210.73, 0, 27.38, 2.12, 76.51, 
76.51)), .Names = c("ID", "Age.Code", "Memory.Code", "Compound_A"
), class = "data.frame", row.names = c(NA, -26L))

Answer 1

Here's a ggplot solution.

library(ggplot2)
ggplot(data, aes(x=factor(Memory.Code),y=Compound_A))+
  geom_boxplot(aes(fill=factor(Age.Code)),position=position_dodge(.9))+
  scale_fill_discrete(name="Age.Code")+labs(x="Memory.Code")

Here's the way using base R.

boxplot(Compound_A~factor(Age.Code)+factor(Memory.Code),data)