[R] changing number of axis

[Deepayan Sarkar]

On Tue, Sep 29, 2009 at 11:09 PM, Dan Kortschak
<dan.kortschak at adelaide.edu.au> wrote:
> Hi Deepayan,
>
> Thanks for that, I had a think (a few hour too late) and came to the
> same conclusion. I had wanted to have vertical bars for each of the data
> points, I have gone to a straight xyplot and this shows other intersting
> information - maybe I want to be able to do both point and bar plots
> (the bars show gaps in the bins nicely where the points don't).

Perhaps  type = c("l", "h") in xyplot.

-Deepayan

> I'm thinking there is probably a better way to do it that what I was
> trying, a vertical line from y=0 to y=binvalue for each represented bin
> seem most sensible, but I'm not sure how to go about this.
>
> thanks
> Dan
>
>
> On Tue, 2009-09-29 at 22:59 -0700, Deepayan Sarkar wrote:
>> On Wed, Sep 16, 2009 at 2:02 PM, Dan Kortschak
>> <dan.kortschak at adelaide.edu.au> wrote:
>> > Hi, I trying to produce a bar chart describing hits to specific bins by
>> > chromosome for a large data set (I am asking here because
>> > experimentation with options is precluded due to this - generating the
>> > figure takes about an hour):
>> >
>> > barchart(hits~bin|chromosome, data=hits, horizontal=FALSE, origin=0,
>> > lab=c(3,10), layout=c(1,5,5), strip=strip.custom(style=3, bg="grey90",
>> > par.strip.text=list(cex=0.5)), as.table=TRUE);
>> >
>> > I have about 2500 bins for the largest factor and barchart is drawing
>> > tick labels for a substantial proportion of these (how many, I can't see
>> > since due to the density of the labels).
>>
>> Probably all 2500 of them.
>>
>> > My question is how I can get a sane number of labels along the x axis
>> > (about 5-10 would be good). I suspect that 'scales' might be the way to
>> > go, but I can't see an obvious option to do this.
>>
>> Basically, barchart has to be convinced that the limits are numeric.
>> There are various ways to do that; the simplest is to provide a
>> numeric 'xlim', e.g.,
>>
>> df <- data.frame(y = runif(100), x = gl(100, 1))
>> barchart(y ~ x, df, origin = 0)
>> barchart(y ~ x, df, origin = 0, xlim = c(0, 101))
>>
>> However, you should also rethink the use of barchart for a 2500-level
>> factor; at a minimum, consider something like
>>
>> xyplot(y ~ as.numeric(x), df, type = "h")
>>
>> -Deepayan
>
>