Scatterplot Showing All Points

On 18/12/2007 7:31 AM, Antony Unwin wrote:

Wayne,

Try the iplot command in iPlots.  You can then vary both the  
pointsize and the transparency of your scatterplot interactively and  
decide which scatterplot conveys the information best.  Sometimes  
it's helpful to use more than one scatterplot when presenting your  
results.

(I must admit to being very surprised that jittering and sunflower  
plots have been suggested for a dataset of 5000 points.  Do those who  
mentioned these methods have examples on that scale where they are  
effective?)

Sure.  The original post said there were about 50-60 unique locations. 
This plot:

x <- rbinom(5000, 20, 0.15)
y <- rbinom(5000, 20, 0.15)
plot(x,y)

has a few more unique locations; tune those probabilities if you want it 
closer.  Due to the overlap, the distribution is very unclear.  But this 
plot

plot(jitter(x), jitter(y))

makes the distribution quite clear.

I wouldn't use the default pch if I had 50000 points, but with pch=".", 
it's not so bad even in that case.

Duncan Murdoch