Hi Guys I have two data frames which I would like to merge on two conditions. I am doing the following (abstract form) new.data.frame <- merge(df1,df2, by=c("Col1","Col2")) It is giving me a null result. Basically I need to apply two conditions. I also tried sqldf but it is running forever. Will indexing help ? temp <- sqldf("select a.chr,a.SNP,a.snp_qual,a.rms_qual,a.depth,b.rsid FROM + data_lane6_snps a, + data_lane6_snps_rsid b + WHERE + a.SNP = b.SNP + AND + a.chr = b.chr + ") Thanks! -Abhi [[alternative HTML version deleted]]
On Apr 6, 2010, at 3:54 PM, Abhishek Pratap wrote:> Hi Guys > > I have two data frames which I would like to merge on two conditions. > > I am doing the following (abstract form) > > new.data.frame <- merge(df1,df2, by=c("Col1","Col2"))What does str(df1) ; str(df2) ... show?> > It is giving me a null result. > > Basically I need to apply two conditions. > > I also tried sqldf but it is running forever. Will indexing help ? > > temp <- sqldf("select > a.chr,a.SNP,a.snp_qual,a.rms_qual,a.depth,b.rsid FROM > + data_lane6_snps a, > + data_lane6_snps_rsid b > + WHERE > + a.SNP = b.SNP > + AND > + a.chr = b.chr > + ") > > Thanks! > -Abhi > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list > 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.David Winsemius, MD West Hartford, CT
Yes, indexing will typically make a large difference. On Tue, Apr 6, 2010 at 3:54 PM, Abhishek Pratap <abhishek.vit at gmail.com> wrote:> Hi Guys > > I have two data frames which I would like to merge on two conditions. > > I am doing the following ?(abstract form) > > new.data.frame <- merge(df1,df2, by=c("Col1","Col2")) > > It is giving me a null result. > > Basically I need to apply two conditions. > > I also tried sqldf but it is running forever. Will indexing help ? > > temp <- sqldf("select a.chr,a.SNP,a.snp_qual,a.rms_qual,a.depth,b.rsid FROM > + data_lane6_snps a, > + data_lane6_snps_rsid b > + WHERE > + a.SNP = b.SNP > + AND > + a.chr = b.chr > + ") > > Thanks! > -Abhi > > ? ? ? ?[[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list > 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. >