[R] selecting the COLUMNS in a dataframe function of the numerical values in a ROW

[Bogdan Tanasa]

very helpful, thanks a lot !

On Thu, Nov 1, 2018 at 9:59 PM William Michels <wjm1 using caa.columbia.edu>
wrote:

> Perhaps one of the following two methods:
>
> > zgene = data.frame(  TTT=c(0,1,0,0),
> +                TTA=c(0,1,1,0),
> +                 ATA=c(1,0,0,0),
> +                  ATT=c(0,0,0,0),
> +                 row.names=c("gene1", "gene2", "gene3", "gene4"))
> > zgene
>       TTT TTA ATA ATT
> gene1   0   0   1   0
> gene2   1   1   0   0
> gene3   0   1   0   0
> gene4   0   0   0   0
> >
> > zgene[ , zgene[2,1:4] > 0]
>       TTT TTA
> gene1   0   0
> gene2   1   1
> gene3   0   1
> gene4   0   0
> >
> > zgene[ , zgene[rownames(zgene) == "gene2",1:4] > 0]
>       TTT TTA
> gene1   0   0
> gene2   1   1
> gene3   0   1
> gene4   0   0
> >
>
> Best Regards,
>
> Bill.
>
> William Michels, Ph.D.
>
>
>
> On Thu, Nov 1, 2018 at 9:07 PM, Bogdan Tanasa <tanasa using gmail.com> wrote:
> > Dear Bill, and Bill,
> >
> > many thanks for taking the time to advice, and for your suggestions. I
> > believe that I shall rephrase a bit my question, with a better example :
> > thank you again in advance for your help.
> >
> > Let's assume that we start from a data frame :
> >
> > x = data.frame(  TTT=c(0,1,0,0),
> >                TTA=c(0,1,1,0),
> >                 ATA=c(1,0,0,0),
> >                  ATT=c(0,0,0,0),
> >                 row.names=c("gene1", "gene2", "gene3", "gene4"))
> >
> > Shall we select "gene2", at the end, we would like to have ONLY the
> COLUMNS,
> > where "gene2" is NOT-ZERO. In other words, the output contains only the
> > first 2 columns :
> >
> > output = data.frame(  TTT=c(0,1,0,0),
> >                                    TTA=c(0,1,1,0),
> >                                    row.names=c("gene1", "gene2", "gene3",
> > "gene4"))
> >
> >  with much appreciation,
> >
> > -- bogdan
> >
> > On Thu, Nov 1, 2018 at 6:34 PM William Michels <wjm1 using caa.columbia.edu>
> > wrote:
> >>
> >> Hi Bogdan,
> >>
> >> Are you saying you want to drop columns that sum to zero? If so, I'm
> >> not sure you've given us a good example dataframe, since all your
> >> numeric columns give non-zero sums.
> >>
> >> Otherwise, what you're asking for is trivial. Below is an example
> >> dataframe ("ygene") with an example "AGA" column that gets dropped:
> >>
> >> > xgene <- data.frame(TTT=c(0,1,0,0),
> >> +                TTA=c(0,1,1,0),
> >> +                ATA=c(1,0,0,0),
> >> +                gene=c("gene1", "gene2", "gene3", "gene4"))
> >> >
> >> > xgene[ , colSums(xgene[,1:3]) > 0 ]
> >>   TTT TTA ATA  gene
> >> 1   0   0   1 gene1
> >> 2   1   1   0 gene2
> >> 3   0   1   0 gene3
> >> 4   0   0   0 gene4
> >> >
> >> > ygene <- data.frame(TTT=c(0,1,0,0),
> >> +                 TTA=c(0,1,1,0),
> >> +                 AGA=c(0,0,0,0),
> >> +                 gene=c("gene1", "gene2", "gene3", "gene4"))
> >> >
> >> > ygene[ , colSums(ygene[,1:3]) > 0 ]
> >>   TTT TTA  gene
> >> 1   0   0 gene1
> >> 2   1   1 gene2
> >> 3   0   1 gene3
> >> 4   0   0 gene4
> >>
> >>
> >> HTH,
> >>
> >> Bill.
> >>
> >> William Michels, Ph.D.
> >>
> >>
> >> On Thu, Nov 1, 2018 at 5:45 PM, Bogdan Tanasa <tanasa using gmail.com> wrote:
> >> > Dear all, please may I ask for a suggestion :
> >> >
> >> > considering a dataframe  that contains the numerical values for gene
> >> > expression, for example :
> >> >
> >> >  x = data.frame(TTT=c(0,1,0,0),
> >> >                TTA=c(0,1,1,0),
> >> >                ATA=c(1,0,0,0),
> >> >                gene=c("gene1", "gene2", "gene3", "gene4"))
> >> >
> >> > how could I select only the COLUMNS where the value of a GENE (a ROW)
> is
> >> > non-zero ?
> >> >
> >> > thank you !
> >> >
> >> > -- bogdan
> >> >
> >> >         [[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.
>

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