R scientific notation in plots

Question

I have a simple plot:

#!/usr/bin/Rscript                                                                                    

png('plot.png')

y <- c(102, 258, 2314)                                                                         
x <- c(482563, 922167, 4462665)

plot(x,y)
dev.off()

R uses 500, 1000, 1500, etc for the y axis. Is there a way I can use scientific notation for the y axis and put * 10^3 on the top of the axis like the figure below?

Contusion

Answer 1

This is sort of a hacky way, but there's nothing wrong with it:

plot(x,y/1e3, ylab="y /10^3")

Yard

Thanks. It would be better using expressions #4302867 – Contusion

Answer 2

A similar technique is to use eaxis (extended / engineering axis) from the sfsmisc package.

It works like this:

library(sfsmisc)

x <- c(482563, 922167, 4462665)
y <- c(102, 258, 2314)

plot(x, y, xaxt="n", yaxt="n")

eaxis(1)  # x-axis
eaxis(2)  # y-axis

Dneprodzerzhinsk

Answer 3

How you get the labels onto your axis depends upon the used plotting system.(base, ggplot2 or lattice) You can use functions from scales package to format your axis numbers:

library(scales)
x <- 10 ^ (1:10)
scientific_format(1)(x)
[1] "1e+01" "1e+02" "1e+03" "1e+04" "1e+05" "1e+06" "1e+07" "1e+08" "1e+09" "1e+10"

Here an example using ggplot2 :

library(ggplot2)
dat <- data.frame(x  = c(102, 258, 2314),                                                                     
                  y  = c(482563, 922167, 4462665))

qplot(data=dat,x=x,y=y) + 
  scale_y_continuous(label=scientific_format(digits=1))+ 
  theme(axis.text.y =element_text(size=50))

EDIT The OP has a specific need. Here some ideas I used here in order to accomplish this :

1. You can customize your plot labels using axis function.
2. Use mtext to put text in the outer plot region
3. Use expression to profit from the plotmath features...

y <- c(102, 258, 2314)                                                                         
x <- c(482563, 922167, 4462665)
plot(x,y,ylab='',yaxt='n')
mtext(expression(10^3),adj=0,padj=-1,outer=FALSE)
axis(side=2,at=y,labels=round(y/1000,2))

Pedaiah

I guess you misunderstood my question; I want 1, 2, 3, 4 with y axis and e+06 to be on the top of the y axis. – Contusion

No I understand perfectly your need. My answer was general to invite you to discover R plots features and not to try to reproduce some MATLAB features. Many default R parameters are optimized to easily extract the information from a plot. e.g putting the 10^3, make the plot harder to understand , we are obliged to rescale each time we follow a point... – Pedaiah

I understand that, I'm going to put this into a paper and saving space is my priority here. – Contusion