[BioC] comparing data frames

John Zhang jzhang at jimmy.harvard.edu
Tue May 4 18:17:57 CEST 2004

>I have two data frames with a name column containing affy probeset ids. I would 
like to pull out the ids (just the ids) which are common in both data frames. 
(Actually, I could just have to character vectors and would like to print the 
common elements).
>I tried this approach:
>for (elx in x) {for (ely in y) {if (elx==ely) print(ely)}}
>x, y : character vectors

Would this work for you:

> d1 <- data.frame(matrix(1:20, ncol = 4))
> d2 <- data.frame(matrix(3:22, ncol = 4))
> tt <- intersect(d1[,1], d2[,1])
> d1[d1[,1] %in% tt,] 

>This prints out the correct result but I am not able to assign the resulting 
probesets and it also seems quite an inelegant solution.
>Thank you for your help.
>Juerg Straubhaar
>UMass Med School
>Bioconductor mailing list
>Bioconductor at stat.math.ethz.ch

Jianhua Zhang
Department of Biostatistics
Dana-Farber Cancer Institute
44 Binney Street
Boston, MA 02115-6084

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