An Example of Doing a Matrix Plot in Base R

The matplot function is Base R is a great way to visualize matrix data to look for relationships. It is a very flexible format that allows a use to plot data as points, lines or a combination of both. Matplot is often forgotten about but useful plot.

For the first example I have upload the weekly individual scores of the playes in my fantasy football league.

player1<-c(140,131,80,73,74,101,82,67,81,77,112,79)
player2<-c(110,111,68,118,122,132,116,99,80,97,97,101)
player3<-c(91,135,129,153,131,69,115,129,43,71,74,68)
player4<-c(137,103,119,128,83,98,99,86,127,113,102,117)
player5<-c(124,85,117,100,77,98,105,95,177,96,124,123)
player6<-c(138,135,82,122,69,121,65,117,96,90,113,88)
player7<-c(109,107,70,125,69,81,102,78,190,115,108,99)
player8<-c(161,95,120,173,122,145,138,158,143,127,100,113)
scores<-cbind(player1,player2,player3,player4,player5,player6,player7,player8)
rownames(scores)<-c("week1","week2","week3","week4","week5","week6","week7","week8","week9","week10","week11","week12")

Now lets plot it in the most basic way

matplot(scores)

It is ok, but not really readable. Inorder to help with that lets change this to from the default numbered point to a dot line and add a legend to the x-axis and a Main title.

matplot(scores,type="o",pch=20,main="Data Scientist's Fantasy Football",xlab="Week")

 Now it is much more readable how about we add a mean indicating the mean scores to the entire league and add it to the plot.

matplot(scores,type="o",pch=20,main="Data Scientist's Fantasy Football",xlab="Week")
abline(h=mean(scores),lwd=2)

So that is matplot pretty easy and pretty useful.