[R] barplot

[Jim Lemon]

On 05/23/2012 09:34 PM, bets wrote:
> Hey,
>
> I am trying to create barplot of abundances over time (in days). The period
> is over 171 days, so I don't want to have all labels there but only the
> first day of the month. I couldn't find anything like this on the forum yet.
> Mostrly it's about year to year data.
>
> This is the relevant part of my table:
>
> datum	month	abundance
> 26/03/11	 March	1
> 27/03/11	 March	0
> 28/03/11	 March	1
> 29/03/11	 March	0
> 30/03/11	 March	0
> 31/03/11	 March	0
> 1/04/11	 April	0
> 2/04/11	 April	0
> 3/04/11	 April	0
> ...
> 9/09/11 September 1
>
> I tried making a sequence:
> hatch$axis.ticks2=seq(from=hatch$datum[1],to=hatch$datum[171], by=30)
> But this sequence is too short to use the names.arg function.
> Next, I tried more ideas from this forum that might work. But the best I got
> was by just replacing the day by a month and reducing the size of the
> tickmarks. Or by blanking excessive labels in R commander. But this is
> really poor substitute of what I actually want. Furthermore, in the end I
> want the labels vertical to match other graphs (las=2), but when doing that
> my labels become so dense it's basically one black blur.
>
> bar=barplot(abundance, col="black",xlab="", ylim=c(0,120), axisnames=T,
> ylab="Total fish",axis.lty=1)
> axis(1,at=bar, tcl=-0.01, las=1,lab=hatch$month,cex.axis=0.8)
>
Hi bets,
So you have 171 bars with most of them 0? If you want to use "barplot", 
drop the x axis:

barplot(...,xaxt="n",...)

and then display an x axis with, let's see, seven labels. Something like:

axis(1,at=seq(as.Date("2011-03-15"),as.Date("2011-09-09"),by=30),
  labels=month.abbr[3:9])

If they don't all display, try "staxlab" in the plotrix package.

Jim