[R] calculating area of ellipse

David Winsemius dw|n@em|u@ @end|ng |rom comc@@t@net
Fri May 7 04:31:50 CEST 2021


On 5/6/21 6:29 PM, Jim Lemon wrote:
> Hi James,
> If the result contains the major (a) and minor (b) axes of the
> ellipse, it's easy:
>
> area<-pi*a*b


ITYM semi-major and semi-minor axes.


-- 

David

>
> try using str() on the result you get.
>
> Jim
>
> On Fri, May 7, 2021 at 3:51 AM james meyer <meyer.james using usa.net> wrote:
>> In doing meta-analysis of diagnostic accuracy I produce ellipses of confidence
>> and prediction intervals in two dimensions.  How can I calculate the area of
>> the ellipse in ggplot2 or base R?
>>
>> thank you
>> James Meyer
>>
>> ______________________________________________
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> ______________________________________________
> R-help using 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.



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