Re: [R] counting the number of rows that satisfy a certain criteria
Hi, Try: set.seed(42) X <- as.data.frame(matrix(sample(0:1, 4*50,replace=TRUE), ncol=4)) table(X[1:2])[4] #[1] 15 sum(rowSums(X[1:2])==2) #[1] 15 A.K. On Saturday, June 21, 2014 10:59 AM, Kate Ignatius wrote: I have 4 columns, and about 300K plus rows with 0s and 1s. I'm trying to count how many rows satisfy a certain criteria... for instance, how many rows are there that have the first column == 1 as well as the second column == 1. I've tried using rowSums and colSums but it keeps giving me this type of error: Error in rowSums(X[1] == 1 & X[2] == 1) : 'x' must be an array of at least two dimensions Thanks in advance! __ R-help@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@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.
Re: [R] counting the number of rows that satisfy a certain criteria
Thanks! On Sat, Jun 21, 2014 at 11:05 AM, Jorge I Velez wrote: > Hi Kate, > > You could try > > sum(X[, 1] == 1 & X[, 2] == 1) > > where X is your data set. > > HTH, > Jorge.- > > > > On Sun, Jun 22, 2014 at 12:57 AM, Kate Ignatius > wrote: >> >> I have 4 columns, and about 300K plus rows with 0s and 1s. >> >> I'm trying to count how many rows satisfy a certain criteria... for >> instance, how many rows are there that have the first column == 1 as >> well as the second column == 1. >> >> I've tried using rowSums and colSums but it keeps giving me this type of >> error: >> >> Error in rowSums(X[1] == 1 & X[2] == 1) : >> 'x' must be an array of at least two dimensions >> >> Thanks in advance! >> >> __ >> R-help@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@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.
Re: [R] counting the number of rows that satisfy a certain criteria
Hi Kate, You could try sum(X[, 1] == 1 & X[, 2] == 1) where X is your data set. HTH, Jorge.- On Sun, Jun 22, 2014 at 12:57 AM, Kate Ignatius wrote: > I have 4 columns, and about 300K plus rows with 0s and 1s. > > I'm trying to count how many rows satisfy a certain criteria... for > instance, how many rows are there that have the first column == 1 as > well as the second column == 1. > > I've tried using rowSums and colSums but it keeps giving me this type of > error: > > Error in rowSums(X[1] == 1 & X[2] == 1) : > 'x' must be an array of at least two dimensions > > Thanks in advance! > > __ > R-help@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. > [[alternative HTML version deleted]] __ R-help@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] counting the number of rows that satisfy a certain criteria
I have 4 columns, and about 300K plus rows with 0s and 1s. I'm trying to count how many rows satisfy a certain criteria... for instance, how many rows are there that have the first column == 1 as well as the second column == 1. I've tried using rowSums and colSums but it keeps giving me this type of error: Error in rowSums(X[1] == 1 & X[2] == 1) : 'x' must be an array of at least two dimensions Thanks in advance! __ R-help@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.
