如何使用R中的绘图功能更改散点图中x轴和y轴标签的字体大小和颜色？

Question

I used the following code to draw a scatterplot. How to increase the font size and change colour of x-axis and y-axis label?

data=read.csv("data.csv") 
plot(data$column1,data$column2,xlab="x axis", ylab="y axis",  pch=19)

Answer 1

Look at ?par for the various graphics parameters.

In general cex controls size, col controls colour. If you want to control the colour of a label, the par is col.lab , the colour of the axis annotations col.axis , the colour of the main text, col.main etc. The names are quite intuitive, once you know where to begin.

For example

x <- 1:10
y <- 1:10

plot(x , y,xlab="x axis", ylab="y axis",  pch=19, col.axis = 'blue', col.lab = 'red', cex.axis = 1.5, cex.lab = 2)

If you need to change the colour / style of the surrounding box and axis lines, then look at ?axis or ?box , and you will find that you will be using the same parameter names within calls to box and axis.

You have a lot of control to make things however you wish.

eg

plot(x , y,xlab="x axis", ylab="y axis",  pch=19,  cex.lab = 2, axes = F,col.lab = 'red')
box(col = 'lightblue')
axis(1, col = 'blue', col.axis = 'purple', col.ticks = 'darkred', cex.axis = 1.5, font = 2, family = 'serif')
axis(2, col = 'maroon', col.axis = 'pink', col.ticks = 'limegreen', cex.axis = 0.9, font =3, family = 'mono')

Which is seriously ugly, but shows part of what you can control

Answer 2

To track down the correct parameters you need to go first to ?plot.default , which refers you to ?par and ?axis :

plot(1, 1 ,xlab="x axis", ylab="y axis",  pch=19,
           col.lab="red", cex.lab=1.5,    #  for the xlab and ylab
           col="green")                   #  for the points

Answer 3

Taking DWins example.

What I often do, particularly when I use many, many different plots with the same colours or size information, is I store them in variables I otherwise never use. This helps me keep my code a little cleaner AND I can change it "globally".

Eg

clab = 1.5
cmain = 2
caxis = 1.2

plot(1, 1 ,xlab="x axis", ylab="y axis",  pch=19,
           col.lab="red", cex.lab=clab,    
           col="green", main = "Testing scatterplots", cex.main =cmain, cex.axis=caxis) 

You can also write a function, doing something similar. But for a quick shot this is ideal. You can also store that kind of information in an extra script, so you don't have a messy plot script:

which you then call with setwd("") source("plotcolours.r")

in a file say called plotcolours.r you then store all the eg colour or size variables

clab = 1.5
cmain = 2
caxis = 1.2 

for colours could use

darkred<-rgb(113,28,47,maxColorValue=255)

as your variable 'darkred' now has the colour information stored, you can access it in your actual plotting script.

plot(1,1,col=darkred)