[R] barplot y axis too short

[David Winsemius]

On Feb 1, 2010, at 7:48 PM, David Winsemius wrote:

>
> On Feb 1, 2010, at 7:11 PM, Jack Siegrist wrote:
>
>>
>> Hello,
>>
>> The function barplot automatically creates a y-axis that doesn't  
>> necessarily
>> cover the range of y-values to be plotted. I know how to manually  
>> create my
>> own y-axis so that it does cover the range, but I was wondering if  
>> there is
>> some parameter to change so that the scale of the y-axis is  
>> automatically
>> taller than the tallest bar.
>>
>> I thought setting xpd=F would do it, since it says that xpd  
>> determines
>> whether bars will be plotted outside of the plotting region, but it  
>> had no
>> effect, so I guess it must be dealing with something different.
>>
>> In the example below, the scale goes to 15 but the second bar goes  
>> to 16. In
>> this case I would like the scale to go to 20.
>>
>> Thanks
>>
>> #example data
>> data <- c(12, 16)
>>
>> #none of the following are any different
>> barplot(data)
>> barplot(data, xpd=T)
>> barplot(data, xpd=F)
>
> barplot(data, xpd=F, yaxp=c(0,max(data), 4)  )

That gets you a 16-tick but not the desired range to 20.

 > barplot(data,  yaxp=c(0,20, 4) )

#does not "work" in the senses that the range goes off-plot and the  
"20" cannot be seen.

 > barplot(data,  yaxp=c(0,20, 4), ylim=c(0,20) )  # "Works"

>> -- 

>

David Winsemius, MD
Heritage Laboratories
West Hartford, CT