Thank you! > On Jun 20, 2016, at 12:41 PM, David L Carlson <[email protected]> wrote: > > It does not test the first column, but a vector must have consecutive > indices. Since you did not assign a value, R inserts a missing value. If you > don't want to see it use > >> results.pc.all[, -1] > [,1] [,2] > results.2 1 2 > results.3 2 3 > > ------------------------------------- > David L Carlson > Department of Anthropology > Texas A&M University > College Station, TX 77840-4352 > > -----Original Message----- > From: R-help [mailto:[email protected]] On Behalf Of Brittany > Demmitt > Sent: Monday, June 20, 2016 12:15 PM > To: [email protected] > Subject: [R] loop testing unidentified columns > > Hello, > > I want to compare all of the columns of one data frame to another to see if > any of the columns are equivalent to one another. The first column in both of > my data frames are the sample IDs and do not need to be compared. Below is an > example of the loop I am using to compare the two data frames that counts the > number of equivalent values there between two columns. So in this example the > value of 3 means that all three observations for the two columns being > compared were equivalent. The loop works fine but I do not understand why it > tests the first column of the sample IDs providing “NA” for the sum of > matching when my loop is specifying to only test columns 2-3. > > Thank you! > > > #create dataframe A > A = matrix(c("a",3,4,"b",5,7,"c",3,7),nrow=3, ncol=3,byrow = TRUE) > A <- as.data.frame(A) > A$V2 <- as.numeric(A$V2) > A$V3 <- as.numeric(A$V3) > str(A) > > #create dataframe B > B = matrix(c("a",1,1,"b",6,2,"c",2,2),nrow=3, ncol=3,byrow = TRUE) > B <- as.data.frame(B) > B$V2 <- as.numeric(B$V2) > B$V3 <- as.numeric(B$V3) > str(B) > > results.2 <- numeric() > results.3 <- numeric() > > > #compare columns to identify those that are identical in the two dataframes > for(i in 2:3){ > results.2[i] <- sum(A[,2]==B[,i]) > results.3[i] <- sum(A[,3]==B[,i]) > results.pc.all <- rbind(results.2,results.3) > } > results.pc.all > > ______________________________________________ > [email protected] 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.
______________________________________________ [email protected] 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.
