Extract rows from data frame based on row names from anotherdata frame
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
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