[R] change axis labels and text size in "splom"

[Xiaoqi Cui]

Hi everyone:

I'm using "splom" to draw scatterplot matrix. I'm wondering how can I change the axis labels to c(1,10,100,1000,...) 
instead of c(1,2,3,...), and also how can I change the text size (for labels)?

Thanks a lot!
xcui