[R] is there is a way to extract lines in between 3 files that are in common based on one column?

[Ana Marija]

Hi Jim,

thank you so much for getting back to me. I tried your code and this is
what I get:
> dim(neu2)
[1] 3740988       9
> dim(nep2)
[1] 3740988       9
> dim(ret2)
[1] 3740001       9

I think I would need to have the same number of lines in all 3 data frames.

Can you please advise.

Cheers
Ana

On Mon, Jun 1, 2020 at 7:31 PM Jim Lemon <drjimlemon using gmail.com> wrote:

> Hi Ana,
> Not too hard, but your example has all the "marker" fields in common.
> So using a sample that will show the expected result:
>
> neu1<-read.table(text="Chr BP Marker  MAF A1 A2 Direction  pValue N
>  1 100000012 1:100000012:G:T 0.229925  T  G  + 0.650403 1594
>  1 100000827 1:100000827:C:T 0.287014  T  C  + 0.955449 1594
>  1 100002713 1:100002713:C:T 0.097867  T  C  - 0.290455 1594
>  1 100002882 1:100002882:T:G 0.287014  G  T  + 0.955449 1594
>  1 100002991 1:100002991:G:A 0.097867  A  G  - 0.290455 1594
>  1 100004726 1:100004726:G:A 0.132058  A  G  + 0.115005 1594",
>  header=TRUE,stringsAsFactors=FALSE)
>
> nep1<-read.table(text="Chr BP Marker MAF A1 A2 Direction    pValue N
>  1 100000012 1:100000012:G:T 0.2300430 T  G - 0.1420030 1641
>  1 100000827 1:100000827:C:T 0.2867150 T  C - 0.2045580 1641
>  1 100002713 1:100002713:C:T 0.0975015 T  C - 0.0555507 1641
>  1 100002882 1:100002882:T:G 0.2867150 G  T - 0.2045580 1641
>  1 100002991 1:100002991:G:A 0.0975015 A  G - 0.0555507 1641
>  1 100004726 1:100004727:G:A 0.1325410 A  G - 0.8725660 1641",
>  header=TRUE,stringsAsFactors=FALSE)
>
> ret1<-read.table(text="Chr BP Marker MAF A1 A2 Direction   pValue N
>  1 100000012 1:100000012:G:T 0.2322760 T  G - 0.230383 1608
>  1 100000827 1:100000827:C:T 0.2882460 T  C - 0.120356 1608
>  1 100002713 1:100002713:C:T 0.0982587 T  C - 0.272936 1608
>  1 100002882 1:100002882:T:G 0.2882460 G  T - 0.120356 1608
>  1 100002991 1:100002992:G:A 0.0982587 A  G - 0.272936 1608
>  1 100004726 1:100004727:G:A 0.1340170 A  G - 0.594538 1608",
> header=TRUE,stringsAsFactors=FALSE)
>
> # merge the three data frames on "Marker"
> nn1<-merge(neu1,nep1,by="Marker")
> nn2<-merge(nn1,ret1,by="Marker")
> # get the common "Marker" strings
> Marker3<-nn2$Marker
> # subset all three data frames on Marker3
> neu2<-neu1[neu1$Marker %in% Marker3,]
> nep2<-nep1[nep1$Marker %in% Marker3,]
> ret2<-ret1[ret1$Marker %in% Marker3,]
>
> Jim
>
> On Tue, Jun 2, 2020 at 7:50 AM Ana Marija <sokovic.anamarija using gmail.com>
> wrote:
> >
> > Hello,
> >
> > I have 3 data frames which have about 3.4 mill lines (but they don't have
> > exactly the same number of lines)...they look like this:
> > ...
> > Is there is a way to create another 3 data frames, say neu2, nep2, ret2
> > which would only contain lines that have the same entries in Marker
> column
> > for all 3 data frames?
> >
> > Thanks
> > Ana
> >
> >         [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > 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.
>

	[[alternative HTML version deleted]]