Hi all, Is there a function to extract row names from a data frame based on row names from another data frame? I can write a loop function to do this, but this may be inefficient in terms of processing. thanks for any information, Wade
Extract rows from data frame based on row names from another data frame
3 messages · Wade Wall, Daniel Malter, David Winsemius
Hi #Create data and data frames x=rnorm(5,0,1) y=rnorm(5,0,1) z=rnorm(5,0,1) d1=data.frame(x,y) d2=data.frame(y,z) #which variable name in d2 is a variable name in d1? names(d2[names(d2)%in%names(d1)]) # it's y #give me the columns of d2 that have variable names #that are also variable names in d1 d2[names(d2)==names(d2[names(d2)%in%names(d1)])] #check d2$y Cheers, Daniel ------------------------- cuncta stricte discussurus ------------------------- -----Urspr?ngliche Nachricht----- Von: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] Im Auftrag von Wade Wall Gesendet: Thursday, December 11, 2008 3:59 PM An: r-help at stat.math.ethz.ch Betreff: [R] Extract rows from data frame based on row names from anotherdata frame Hi all, Is there a function to extract row names from a data frame based on row names from another data frame? I can write a loop function to do this, but this may be inefficient in terms of processing. thanks for any information, Wade ______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
1 day later
Matching row names was the request. # continuing with your example: rownames(d1)<- letters[1:5] rownames(d2)<- letters[3:7] # and then for rownames of d1 that are also in rownames of d2: # for the full rows ... d1[row.names(d1) %in% row.names(d2),] # or for just the names: rownames(d1)[row.names(d1) %in% row.names(d2)] -- David Winsemius
On Dec 11, 2008, at 4:21 PM, Daniel Malter wrote:
Hi #Create data and data frames x=rnorm(5,0,1) y=rnorm(5,0,1) z=rnorm(5,0,1) d1=data.frame(x,y) d2=data.frame(y,z) #which variable name in d2 is a variable name in d1? names(d2[names(d2)%in%names(d1)]) # it's y #give me the columns of d2 that have variable names #that are also variable names in d1 d2[names(d2)==names(d2[names(d2)%in%names(d1)])] #check d2$y Cheers, Daniel ------------------------- cuncta stricte discussurus ------------------------- -----Urspr?ngliche Nachricht----- Von: r-help-bounces at r-project.org [mailto:r-help-bounces at r- project.org] Im Auftrag von Wade Wall Gesendet: Thursday, December 11, 2008 3:59 PM An: r-help at stat.math.ethz.ch Betreff: [R] Extract rows from data frame based on row names from anotherdata frame Hi all, Is there a function to extract row names from a data frame based on row names from another data frame? I can write a loop function to do this, but this may be inefficient in terms of processing. thanks for any information, Wade
______________________________________________ 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. ______________________________________________ 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.