Two boxplot from a dataset, using different rows

[naufrago]

Dear all,
I am a student who is using R for university, and I'm a beginner, even in this community, so I hope I have posted the question correctly.

I have a dataset, and I would like to create a graph with two boxplots that show and compare the differences in the data. But I would like that the first boxplot is only with the rows 1 to 20 of my dataset, belonging to column 5, while the second boxplot, is only with the rows 21 to 50, always belonging of column 5.

I can't draw this graph. Is it possible? What commands should I use?

Thanks so much for your time

[FJCC]

Here is an example where the data frame has 50 rows. The boxplots use the data from the third column. The first column, called Name, has the value A in the first 20 rows and the value B in rows 21 - 50. ggplot makes separate box plots for each Name.

library(ggplot2)
#invent some data
DF <- data.frame(Name = c(rep("A", 20), rep("B", 30)), B = rnorm(50), C = runif(50))
ggplot(DF, aes(x = Name, y = C)) + geom_boxplot()

^{Created on 2020-08-20 by the reprex package (v0.3.0)}

[naufrago]

Dear FJCC,
thank you very much for your response and availability. In these days I have tried to follow your advice and do something with ggplot, but I did not succeed, I don't undestrand sorry.

I tried to make a drawing of a dataset for example.

If for example I wanted to build in this case, the two boxplots, the first for the variable "experiment 1" with the data of column 8, and rows 3 and 4, while the second comparison boxplot, with the data of rows 5 and 6 (for the "experiment 2"), how should I use the command?

Thanks a lot, sorry

[nirgrahamuk]

Given that you are a self declared beginner. I suggest we focus on making sure you have data in your R environment from which a ggplot2 graph might be made...

Have you imported your data, such that it is a data.frame in R, with a name we can refer to ?
or do you need help with that ? if so , in what form is your data currently ?

[naufrago]

Thank you very much, very kind! My data was in excel format, so I imported it in R in csv format. The name I gave to the dataframe is "d". I used this commands:

setwd ('andress of my dataset')
d <- read.csv('namefile.csv', header = T, sep = ';')
d <- d[,1:21]

Then I ran some tests, and I did some boxplots (not using ggplot), but now, having to compare data on different rows, I got stuck.

I installed ggplot2, using these commands:

install.packages("ggplot2")
library("ggplot2")

Specifically of my dataset, now I should make a boxplot with rows 1 to 26 of column 20 ("experiment 1"), with a second boxplot with the rows 27 to 54 ("experiment 2"), always of column 20, to compare the two treatments.

[FJCC]

If the labeling of the row as belonging to experiment 1 or 2 is in Column3, try

ggplot(d[1:54, ], aes(x = Column3, y = Column20, color = Column3)) + geom_boxplot()

I assumed the column names are Column1, Column2, etc. as in your original post.

[naufrago]

Dear all,
sorry for the late of my reply, I had some inconvenience. Thanks so much for your help, I really appreciat, very kind. FJCC your last command works perfectly. Thanks so much!