Create barplot from data.frame

Question

In R I have a data.frame like the one on the top of the picture.

Is there a possibility to create a barplot like below?

data.frame:

      X1   X2   X3  
 --- ---- ---- ---- 
  A    2   3    4   
  B    4   2    1   
  C    1   NA   NA

Barplot:

----------------------------
|                          |
|       #    #             |
|    #  #    #             |
| #  #  #    #  #          |
| #  #  #    #  #  #    #  |
----------------------------
  X1 X2 X3   X1 X2 X3   x1
     A           B       C

Sorry, this was just an example ;) i want to have a plot like the one i get with the barplot function — ElPatzo
– ElPatzo, Commented May 17, 2013 at 20:38
Probably you want to change the titel of your question? You actually want to create a barplot from a data.frame and not vice versa. — Beasterfield
– Beasterfield, Commented May 17, 2013 at 20:45

Greg Snow · Accepted Answer · 2013-05-17 22:03:45Z

31

Using base graphics you can do this simply:

mydf <- data.frame( X1=c(A=2, B=4, C=1), X2=c(3,2,NA), X3=c(4,1,NA) )
barplot(t(as.matrix(mydf)), beside=TRUE)

Using additional calls to axis can give the labeling more like in the question.

answered May 17, 2013 at 22:03

Greg Snow

49.9k6 gold badges86 silver badges114 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Dennis Nedry Over a year ago

this should be the accepted answer - why use two libraries to do such a simple task?

wordsforthewise Over a year ago

because converting to a matrix and then a table could add a lot of overhead if you have a large df?

Greg Snow Over a year ago

@wordsforthewise, if the df is so large that this overhead is even noticible (let alone a problem) then a barplot is probably not the best visualization of it anyways.

Beasterfield · Accepted Answer · 2014-10-22 07:44:07Z

20

Assuming, that you don't want ascii output, here is a solution using ggplot2:

# load / generate your data
mydf <- data.frame( X1 = c(2,4,1), X2 = c(3,2,NA), x3 = c(4,1,NA), row.names=c("A","B","C") )
mydf$Category  <- row.names(mydf)

# bring your data to long format as needed by ggplot
library(reshape2)
mydf.molten <- melt(mydf, value.name="Count", variable.name="Variable", na.rm=TRUE)

# plot and facet by categories
library(ggplot2)
qplot( data=mydf.molten, x = Variable, y = Count, geom="bar", stat = "identity" ) + facet_wrap( "Category" )

enter image description here

For further details, I'd recommend to consult the ggplot2 manual, especially the chapter about geom_bar and facet_wrap.

edited Oct 22, 2014 at 7:44

answered May 17, 2013 at 20:41

Beasterfield

7,1332 gold badges43 silver badges49 bronze badges

2 Comments

Mona Jalal Over a year ago

got this error with your code:

> mydf.molten <- melt(mydf, value.name="Count", variable.name="Variable", na.rm=TRUE) Using Category as id variables > qplot( data=mydf.molten, x = Variable, y = Count, geom="bar", stat = "identity" ) + facet_wrap( "Category" ) Error: stat_count() must not be used with a y aesthetic. In addition: Warning message:

stat` is deprecated `

cuttlefish44 Over a year ago

@Mona Jalal; ggplot2 has changed since 2013, especially when it upgraded from ver. 1.xxx to 2.xxx.

Collectives™ on Stack Overflow

Create barplot from data.frame

2 Answers 2

3 Comments

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related