[R] comparing 2 long lists in R

Sarah Goslee sarah.goslee at gmail.com
Thu Sep 24 21:57:28 CEST 2015

merge() most likely, but: are these really lists in the R sense?

The correct answer depends on what the format actually is; you need to
use dput() or some other unambiguous way of providing sample data.

Without a reproducible example that includes some sample data provided
using dput() (fake is fine), the code you used, and some clear idea of
what output you expect, it's impossible to figure out how to help you.
Here are some suggestions for creating a good reproducible example:


On Thu, Sep 24, 2015 at 3:43 PM, Bogdan Tanasa <tanasa at gmail.com> wrote:
> Dear all,
> please could you advise on a computationally quick way to compare and merge
> 2 long lists in R;
> the lists are of the following type, for example :
> <> in list 1 :
> chromosome, coordinateA, coordinateB, value1
> chromosome, coordinateC, coordinateC, value2,
> etc
> <> in list 2 :
> chromosome, coordinateX, coordinateY, value6
> chromosome, coordinateZ, coordinateT, value8,
> etc
> In the unified list, if coordinateA=coordinateX, and
> coordinateB=coordinateY, then we write :
> chromosome, coordinateA, coordinateB, value1, coordinateX, coordinateY,
> value6,
> otherwise, we write the individual values :
> chromosome, coordinateA, coordinateB, value1,
> chromosome, coordinateX, coordinateY, value6,
> thanks,
> bogdan
>         [[alternative HTML version deleted]]
and please don't post in HTML.

Sarah Goslee

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