`**Package ‘![VennDiagram][1]’.**` How can I get the list of common objects in each combination?

For e.g. what are the common 44 Genes in interset (similar image got from online)? 

<a href="https://imgbb.com/"><img src="https://i.ibb.co/h2gLjkQ/venn.png" alt="venn" border="0"></a>

I have used below scripts

    Overlap <- calculate.overlap(x = list(BB, BB, BRR))

    Overlap[[1]]

But in this method, I can not find the list of 1761, 466 genes

how these numbers are given? 

Even when I tried `Overlap$a5` , `Overlap$a7`, etc this also not given some of the values correctly?

Could someone help me?



From what I can tell, the `a`s are distributed from top left to right, to bottom. 
i.e.
```
a1 = 1761
a2=126
a3=466
a4=64
a5=44
a6=27
a7=366
```

This is based on:
![enter image description here][1]

    > library("VennDiagram")
    > 
    > gene_list = paste0("GENE", 1:1000)
    > 
    > studies = list( S1=sample(gene_list, 700, replace = FALSE),
    +                 S2=sample(gene_list, 700, replace = FALSE),
    +                 S3=sample(gene_list, 700, replace = FALSE) )
    > 
    > ol = calculate.overlap(x = studies)
    > ol_size=sapply(ol, length)
    > 
    > 
    > venn.diagram(
    +   x = studies,
    +   euler.d = TRUE,
    +   filename = "Euler_3set_scaled.tiff",
    +   cex = 2.5,
    +   cat.cex = 2.5,
    +   cat.pos = 0
    + );
    [1] 1
    > # Get the 63
    > length( setdiff(studies$S1, union(studies$S2, studies$S3)) )
    [1] 63
    > # Confirm order
    > ol_size
     a5  a2  a4  a6  a1  a3  a7 
    351 143 143 134  63  72  72 

And it matches the order from `a1` to `a7` going left-right, top-bottom. 

If you want to be sure of what you're getting, you can use [set operators][2] like  I did with `setdiff()` and `union()`. 


  [1]: https://i.imgur.com/85fPa1e.png
  [2]: https://stat.ethz.ch/R-manual/R-devel/library/base/html/sets.html