Plot multiple lines in one graph

Question

Trying to use ggplot to plot multiple lines into one graph, but not sure how to do so with my dataset. Not sure whether I need to change the datastructure or not (transpose?)

Data looks like this:

Company   2011   2013
Company1  300    350
Company2  320    430
Company3  310    420

I also tried it transposed:

Year   Company1  Company2  Company3
2011   300       320       310 
2013   350       430       420

And for this I can plot 1 of the values using;

ggplot(data=df, aes(x=Year, y=Company1)) + geom_line(colour="red") + geom_point(colour="red", size=4, shape=21, fill="white")

But I don't know how to combine all the companies as I don't have an object 'Company' anymore to group on. Any suggestions?

Beasterfield · Accepted Answer · 2013-06-17T15:05:11.233

56

You should bring your data into long (i.e. molten) format to use it with ggplot2:

library("reshape2")
mdf <- melt(mdf, id.vars="Company", value.name="value", variable.name="Year")

And then you have to use aes( ... , group = Company ) to group them:

ggplot(data=mdf, aes(x=Year, y=value, group = Company, colour = Company)) +
    geom_line() +
    geom_point( size=4, shape=21, fill="white")

enter image description here

edited Jun 17 '13 at 15:05

answered Jun 17 '13 at 14:51

Beasterfield

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`df` won't overwrite `stats::df`, `R` knows which one you're referring to by context. Try it yourself: `df <- data.frame(A=1:10) ; df(df$A, 1, 5)` – Señor O Jun 17 '13 at 14:54
1

@SeñorO That's what I read already multiple times but you are right, it's not overwritten. So as note to myself: Never pass information to someone else without having checked them by myself :-) I edited my question. – Beasterfield Jun 17 '13 at 15:04
1

It can still be a good idea to avoid `df` as a variable name - if you use it often (like I do, against my own advice) then sometimes when you forget to define it, you get the cryptic error "Error in df$foo : object of type 'closure' is not subsettable" instead of something better like "Error: object 'df' not found". – Ken Williams Jan 25 '16 at 04:45

Federico Giorgi · Answer 2 · 2014-03-25T20:00:24.073

18

Instead of using the outrageously convoluted data structures required by ggplot2, you can use the native R functions:

tab<-read.delim(text="
Company 2011 2013
Company1 300 350
Company2 320 430
Company3 310 420
",as.is=TRUE,sep=" ",row.names=1)

tab<-t(tab)

plot(tab[,1],type="b",ylim=c(min(tab),max(tab)),col="red",lty=1,ylab="Value",lwd=2,xlab="Year",xaxt="n")
lines(tab[,2],type="b",col="black",lty=2,lwd=2)
lines(tab[,3],type="b",col="blue",lty=3,lwd=2)
grid()
legend("topleft",legend=colnames(tab),lty=c(1,2,3),col=c("red","black","blue"),bg="white",lwd=2)
axis(1,at=c(1:nrow(tab)),labels=rownames(tab))

R multiple lines plot

edited Mar 25 '14 at 20:00

answered Mar 25 '14 at 19:06

Federico Giorgi

10,495
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4

'outrageously convoluted data structures' more than a bit strong. I find it very helpful to use data in this shape – Epimetheus Sep 10 '16 at 14:50
2

Thank you for the 'outrageously convoluted data structures' statement! Strongly appreciated! – Michal J Figurski Apr 21 '20 at 19:39

score 1 · Answer 3 · answered Jul 27 '18 at 12:29

The answer by @Federico Giorgi was a very good answer. It helpt me. Therefore, I did the following, in order to produce multiple lines in the same plot from the data of a single dataset, I used a for loop. Legend can be added as well.

plot(tab[,1],type="b",col="red",lty=1,lwd=2, ylim=c( min( tab, na.rm=T ),max( tab, na.rm=T ) )  )
for( i in 1:length( tab )) { [enter image description here][1]
lines(tab[,i],type="b",col=i,lty=1,lwd=2)
  } 
axis(1,at=c(1:nrow(tab)),labels=rownames(tab))

Plot multiple lines in one graph

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