# [R] plot circles where z values are circles radius

Jim Lemon drjimlemon at gmail.com
Fri Jan 23 22:50:14 CET 2015

```Hi Alireza,
Part of the problem is the scale of your numbers. You probably want
something like this.

plot(x,y,cex=z/min(z)*2)

What happens here is that the default plotting character, which
happens to be a circle, is plotted in a size relative to the ratio of
each z value to the minimum z value. This is because the default value
of cex is 1. I have multiplied the result by 2 to make what is
happening more obvious. If you want to generate circles with specific
diameters, you will have to scale these to the area of the plot in
user units - see par("usr").

Jim

On Sat, Jan 24, 2015 at 8:29 AM, Thomas Adams <tea3rd at gmail.com> wrote:
> I think what you should look at are these web sites I found with a Google
> search:
>
> http://flowingdata.com/2010/11/23/how-to-make-bubble-charts/
> http://www.r-bloggers.com/bubble-plots-ggplot2/
> http://cran.r-project.org/web/packages/HSAUR/vignettes/Ch_logistic_regression_glm.pdf
> http://cran.r-project.org/web/packages/mapplots/mapplots.pdf
>
>
> Cheers!
> Tom
>
> On Fri, Jan 23, 2015 at 2:12 PM, Dr. Alireza Zolfaghari <
> ali.zolfaghari at gmail.com> wrote:
>
>> Hi there,
>> I am trying to plot z values using Circle symbol. Each x and y has a value
>> which will be plotted using a circle where circle's radius is corrlated
>> with the value of z.
>>
>> I wrote the code , but unable to change the size of circle no matter what I
>> chose for Scale. Any help please?
>>
>> x=c(84390255386 ,84390255386, 78028317380 ,53594648044,422)
>> y=c(949849442 ,941645043, 840135292, 74, 821632939)
>> z=c(0.005641896, 0.005641896 ,0.005641896, 0.007978846,0.007978846)
>>
>>
>> scale=0.3
>>
>> xlims =c(min(x),max(x))
>> ylims =c(min(y),max(y))
>>
>> symbols(x,y, circles=z,  fg='red')
>>
>> thanks
>> Alireza
>>
>>         [[alternative HTML version deleted]]
>>
>> ______________________________________________
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>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

```