[R] Thinking about using two y-scales on your plot?

[hadley wickham]

>  I've got a series of graphs I generate in R to illustrate backup
>  activity.  These are scaled, primarily, in bytes.  But different
>  activities have different costs per byte, and I augment the bytes
>  scale with dollars.
>
>  http://docs.osg.ufl.edu/tsm/current/ext/UFEXCH-MBX01.AD.UFL.EDU-all.html
>
>  So the blue series corresponds to tbe blue dollars scale (and bytes)
>  and the green and red points correspond to the green scale (and
>  bytes).
>
>  Am I being naughty?

It's not a question of being naughty or not, it's what tasks you are
facilitating with your graphic.  In yours, it's very easy to see how
the bytes vary, but while you can read of the costs, you can't easily
compare the red/green and blue symbols.  I think the plot would be
more effective as two plots - one with bytes and one with dollars.

Hadley


-- 
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