Plot multiple lines in one graph [duplicate]

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?

Answer 1

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") 

Answer 2

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))