[Gnuplot-info] Plotting zero on a log scale

[Dave H. <da...@ho...>]

I know, it's mathematically impossible (it tends to disappear towards -ve 
infinity), but bear with me.

Behold the graph over on www.horsfall.org/spamlog.pdf (about 100k); it's a 
daily plot of my email logs, and amongst other things it includes the spam 
that was actually delivered (shown in pink, of course, as opposed to the 
spam that was rejected in red).  I had to use a logarithmic scale because 
of the magnitudes involved, which means around 3rd November was a 
spam-free day (yes, I was surprised as well!).

It looks ugly, so I would like to re-map "0" into "0.1", but I cannot 
think of an elegant way of doing this.

1) Conditional expressions in the "plot" command; yuck.

2) Something like "if ($7 == 0) $7 = 0.1" before the plot; didn't work.

3) Playing with "set zero"; I must've misunderstood how it's used.

4) A pre-filter on the data; that amounts to tampering with it.

So, is there an elegant way to redefine "0" as "0.1", or do I have to 
pollute the "plot" command?

Thanks.

-- 
Dave Horsfall DTM (VK2KFU)  "Bliss is a MacBook with a FreeBSD server."
http://www.horsfall.org/spam.html (and check the home page whilst you're there)